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We've all heard the statistics about water. Water covers 90%
of the earth's surface. The human body is made up of 90% water.
Along with eating five servings of fruits and vegetables, a person
should drink eight glasses of water a day. So, with water such
an important part of our environment, reports of anything that
may result in "unsafe" water have a tendency to make
people nervous.
Water quality has been a national issue for a long time. The passage of the National Clean Water Act in the 1980s reinforced concerns about water quality and led to a great number of water quality studies. Many organizations-state and federal, public and private-monitor and report on water quality. Perhaps the most readily available and commonly viewed information is published by the United States Geological Service (USGS) either alone or in conjunction with other agencies.
I had always thought of the USGS as the people to turn to for topographic maps and information about mineral resources. But in the early 1990s, the USGS expanded its focus to include water monitoring. The national program includes (since 1991) the study of about a third of eastern Washington State. The work in that region has resulted in a number of very colorful and graphically pleasing two- to four-page glossy fact sheets discussing findings on water quality in Washington State. Additionally, in 1998 the USGS wrapped a lot of the information together into a larger circular (#1144) entitled Water Quality in the Central Columbia Plateau, Washington and Idaho, 1992-95. The fact sheets focus on facts: what testing was done, what was found, and to what the findings can be attributed. Circular 1144 consolidates the information from the fact sheets and adds some interpretation.
If one was to briefly read this literature, or to read it as a sole source of information about water quality, the impression likely to be left is the following:
Agriculture is destroying water quality by putting nitrate and pesticides in ground water and choking up surface waters with nutrient- and pesticide-laden sediments.
Is this true? Well, let's look at some of the issues addressed by the USGS water quality findings, explore what they say, and discuss current information that may impact the findings. For additional information, you may want to refer to Table 1, which is text taken directly from the "Summary of Major Issues and Findings" section of USGS Circular 1144. (Note: Table 2 , at the end of this article, provides a listing of current USGS fact sheets on Water Quality for Washington.)
Groundwater
The main, and very strong, finding of the USGS survey is that there is a high concentration of nitrate in groundwater wells in the Columbia Plateau. About 20% of the sampled wells were found with nitrate levels above the US drinking water maximum acceptable standard of 10 ppm, which is actually lower than the 24% national average found by the USGS (Nolan et al., 1998). This does not mean there is nothing to worry about in central Washington, but it does mean that we are not alone.
Since high nitrate concentrations
are linked to areas predominated by agricultural land use, a great
deal of research effort is being made to deal with the issue.
In Washington, both university and federal research scientists,
individually plus in concert with other public and private organizations,
are conducting research on issues including fertilizer management
practices, land management practices (e.g., cover crops for recycling
potential residual soil nitrate nitrogen), and improved irrigation
systems (improved water use efficiency can reduce the potential
for nitrate to move below the zone where plants can extract it).
Additionally, team efforts involving farmers, local community
members, Conservation Districts, and others-in a program called
Ground Water Management Areas (GWMA)-are being developed to work
toward reducing nitrate contamination risk.
The USGS findings on pesticide contamination of groundwater are far from clear-cut. Although some residues were detected, the concentrations were extremely low. Nothing was detected at a level associated with adverse health effects.
Several issues regarding these findings deserve some thought. One most certainly is detection limits. As analytical equipment becomes more technically advanced, smaller and smaller quantities of chemical compounds can be identified and quantified. As pointed out in previous issues of this newsletter, detection alone does not mean that the quantity of compound in question is dangerous to human health (see "Free? Unlikely," December 1998, Issue 152; "Detection Limits and FQPA: How Low Can You Go?" October 1998, Issue 150; "Now You See It, Now You Don't," August 1998, Issue 148).
Another aspect to consider is that the compounds being found are materials that have effectively been banned, including compounds in the chlorinated hydrocarbon family, the group of compounds which includes the well-known insecticide DDT. Registration of the chlorinated hydrocarbon compounds as agricultural pest controls was virtually discontinued by the late 1970s. The USGS interprets finding these pesticides in groundwater as an indication that currently registered pesticides will soon follow. Another interpretation would be that the pesticides currently registered are far less persistent compounds, therefore more likely to degrade before they can be transported to groundwater. One of the many reasons that the chlorinated organocarbon class of compounds is no longer registered for use is their long persistence in the environment. (It was not until more than 20 years after Dieldrin-an insecticide in the same family as DDT- was banned that some of the soil dwelling insect pests that it controlled so effectively started to reoccur as problem pests.)
The principal USGS finding regarding surface water quality was an increase in sediment loading. Associated with this were some slight increases in nutrient and pesticide levels. Essentially, the levels of chemicals found were low enough that there is no potential risk from a human health standpoint and only a slight risk to aquatic life.
Sediment loading has been recognized as a serious problem in central Washington. The largest problem is associated with a specific type of irrigation system: furrow irrigation. The higher technology, higher cost sprinkler or drip irrigation systems have significantly reduced sediment loading. The USGS recognizes that changes to the more advanced irrigation systems have helped in reducing sediment load. The findings also recognize that the use of polyacrylamide (PAM) in furrow irrigation systems helps to reduce sediment loading. In the past five years, use of PAM has increased, and this trend is expected to continue. The changes in irrigation water management systems away from furrow are also continuing. The Franklin Conservation District estimates that in Franklin County (one of the counties in the study area) the furrow-irrigated acreage has decreased from about 15% in 1986 to about 7% today-thus 50% of the former furrow acreage would have lower potential for surface water contamination with sediment.
The agricultural and scientific communities are aware of the importance of water quality and programs are underway to reduce risk potential. Improvement in water management with center pivot and drip type irrigation systems has the potential to decrease sediment load to surface water as well as to decrease nutrient and pesticide movement to ground water. Prototype systems for further refining these technologies through variable rate water application in center pivots offer potential for further improvements in water management that have both economic (production) and environmental implications. Alternative management strategies such as variable rate agrichemical applications and cover crop use for soil surface and nutrient management are being studied by researchers and readily adapted by some growers. And, as previously mentioned, pest control chemicals now in use likely have lower risks associated with them than some of the compounds the USGS water quality survey identified.
The USGS survey points out something that may seem very apparent, but is often forgotten. Human activities alter the environment. Agriculture is not the only activity that impacts water quality, but in rural, farming areas it is the most likely cause of non-point-source impacts on both surface and ground water quality. However, as we advance our understanding of agricultural systems and improve our management practices, we reduce risk of adversely impacting the environment while continuing to produce food, fiber, and other necessary agricultural products. As our ability to accurately detect chemicals in smaller quantities grows, so does our ability to better understand what risks they may or may not pose. New technologies and conscientious producers will help reduce and better target use of agrichemicals for a future of low risk, high quality water and food.
TABLE
2
|
||
Document Title |
Document Number |
Date Issued |
| Organic Compounds and Trace Elements in Freshwater Streambed Sediment and Fish from the Puget Sound Basin | Fact Sheet 105-98 | Sept. 1998 |
| Soil Erosion in the Palouse River Basin: Indications of Improvement | Fact Sheet 069-98 | July 1998 |
| Nutrient Transport in the Major Rivers and Streams of the Puget Sound Basin, Washington | Fact Sheet 009-98 | March 1998 |
| Irrigation and Surface-Water Quality in the Quincy and Pasco Basins, Washington | Fact Sheet 080-97 | Oct. 1997 |
| Nitrate Concentrations in Ground Water of the Central Columbia Plateau | Open File Report 95-445 | June 1997 |
| Pesticides in Public Supply Wells of Washington State | Fact Sheet FS-122-96 | June 1997 |
| Pesticides in Public Supply Wells of the Central Columbia Plateau | Fact Sheet 205-96 | Oct. 1996 |
| Pesticides and Volatile Organic Compounds in Ground and Surface Water of the Palouse Subunit, Washington and Idaho | Fact Sheet 204-96 | Oct. 1996 |
| Organochlorine Pesticides and PCBs in Aquatic Ecosystems of the Central Columbia Plateau | Fact Sheet 170-96 | Sept. 1996 |
| Pesticides Found in Ground Water below Orchards in the Quincy and Pasco Basins | Fact Sheet 171-96 | July 1996 |
| Agricultural Pesticides Found in Ground Water of the Quincy and Pasco Basins | Fact Sheet 240-95 Rev. | July 1996 |
| Are Agricultural Pesticides in Surface Waters of the Central Columbia Plateau? | Fact Sheet 241-95 | July 1996 |
|
Return to Table 1 |
||
Dr. Joan Davenport is a soil scientist with Washington State University in Prosser. She can be reached at jdavenp@tricity.wsu.edu or (509) 786-2226.
Current listings of salmon under the Endangered Species Act have caused major discussions between state and federal agencies regarding the need to restore and enhance riparian buffers along all salmon-bearing, or potential salmon-bearing, water bodies in the state. A large majority of these streams and creeks meander through privately owned agricultural land. Riparian buffers on agricultural land are important to salmon recovery because they
The "Ag Strategy" section of the Governor's salmon plan, "Extinction is Not an Option," focuses on achieving salmon recovery through voluntary measures. Under this plan, agriculture has four years to prove that a voluntary approach can save salmon, at which time a regulatory approach will be implemented if the desired results have not been achieved.
Aldo Leopold-a patron saint of the environmental movement and founder of the Audubon Society-wrote in 1933:
"Most of what needs doing must be done by the farmer himself. There is no conceivable way in which the general public can legislate crab apples, or grape tangles, or plum thickets to grow up on these barren fence rows, road sides and slopes, nor will the resolution or prayers of the city change the depth of next winter's snow nor cause corn shocks to be left in the field to feed the birds. All the non-farming public can do is provide information and incentives on which farmers may act."
Farm Bureau agrees with Leopold's statement that farmers should
be provided incentives for improving aquatic habitat. However,
practices such as planting native vegetation and restoring stream
banks are not cheap. These lands include some of the most productive
and valuable agricultural lands in the state. To ask a landowner
simply to set aside or remove these lands from production could
force many farmers out of business.
Have the urban public provided land-use financial incentives to our farmers before?
The answer is yes. Agricultural producers have achieved extraordinary conservation successes over the years with the help of voluntary, incentive-based programs that promote conservation of fragile soils and wetlands, along with protecting water quality and wildlife habitat. There have been good programs, but all too frequently they have been either under funded or hampered by overly burdensome standards. Unfortunately, many of the conservation programs focus on compliance with preordained standards rather than on achieving goals.
Nonetheless, many
of our present land-use policies are profoundly anti-agriculture.
When a burdensome government regulation forces farm families to
quit using a portion of their land, the government is in essence
posing a triple tax on the landowners. How? First, farmers lose
all production income from the land; second, farmers must continue
to pay taxes on this now unusable land, and; third, the farmers
must continue to pay mortgage payments on the land being set aside.
Now, with multiple listings of threatened or endangered salmon across Washington, it is critical that we look at developing innovative incentive-based approaches to this problem. The agricultural community believes there are numerous ways that riparian buffers could be established to develop more fish-friendly streams while also allowing agricultural production. Many positive conservation practices have been implemented in farm country for years, such as planting native shrubs and trees, grassed waterways, and filter strips.
History has shown that one-size-fits-all standards simply don't achieve the best results in terms of conservation practices. The more flexible the rules remain, the more problems farmers will solve. The public needs to respect the wide diversity of our agricultural lands and streams through a diverse, workable solution. If this is allowed, the end result will be a win-win situation with healthier salmon habitat, more food being produced to feed a hungry world, and a healthy state economy.
This article is intended to point out
several of the riparian programs available to farmers and to facilitate
open discussion on ways that the agricultural community can meet
the needs of salmon without sacrificing the farm. Farm Bureau
believes we can do both.
The Conservation Reserve Enhancement Program (CREP) is one program that has received a lot of media attention. CREP is a new, voluntary, incentive-based program for farmers and ranchers to establish riparian habitat along spawning areas for salmon and steelhead stocks. In return for planting and maintaining the buffer strips for the length of the contract (10-15 years), farmers will receive rental payments for this idled land from the Natural Resource Conservation Service. CREP is mostly a federally funded program, however, our state provides matching funds.
While this program will not fit the needs of every farmer and rancher in Washington, it does provide one tool for habitat improvement on private property. However, we urge farmers to consider some serious questions before signing up for this program, such as:
Will there be re-enrollment opportunities after the contract expires?
Once land has been planted with trees, will the State Forest Practices Act allow the landowner to either cut or harvest the trees, or does this become a permanent, unusable buffer strip?
There is hope that CREP will be adjusted to be as flexible as
the popular and time-tested Conservation Reserve Program (CRP)
for wheat, which was enacted in the 1980s. This type of flexible
adjustment will only occur if farmers voice their concerns. More
information about this program is available from your local conservation
district office. (Local office numbers are available through the
Conservation Commission. Access them at (360) 407-6200 or http://conserver.org/wcc/cds.html.)
Another incentive-based alternative is USDA's Wildlife Habitat Incentives Program (WHIP). This is a cooperative land-management program, rather than a land-retirement program. WHIP helps landowners protect critically important wildlife habitat by providing both technical assistance and cost-share payments. In addition, if the landowners agree, cooperating state wildlife agencies and nonprofit or private organizations may provide expertise or additional funding to help them enhance a project.
WHIP provides cost-share assistance up to 75 percent of the cost of installing wildlife habitat practices. Cost-share payments may be used to establish new practices or replace practices that fail for reasons beyond the landowner's control. The total cost-share amount cannot exceed $10,000 per agreement. Call your local conservation district office for details.
Still other areas need more consideration:
Historically, many areas in Washington never had trees or shrubs next to salmon-bearing streams and creeks. Thus, fully forested riparian buffers aren't the only solution to saving salmon. There should be a multitude of ways to approach the needs of salmon, and this will require innovative approaches.
Farmers are natural
problem solvers. Once the problem is identified a creative solution
is sure to follow. If the goal is to lower stream water temperature,
farmers should be allowed to plant trees and shrubs and stabilize
stream banks without having to adhere to a predetermined, one-size-fits-all
standard for buffer widths. The landowner should determine whether
the entire stream needs to have a minimum 50-foot-wide stretch
of trees. Perhaps it makes more sense to cluster trees in areas
along the creek, just like Mother Nature does. Salmon are resilient
by nature and will easily swim to the sections along the creek
that have shaded cooler water.
If livestock need to drink at the creek, installing gravel areas in the creek works well. Cattle prefer to drink at more stable areas and will travel several miles to drink from them. This also provides a place where livestock and even vehicles can cross the creek without eroding the banks, compacting streamside soil or damaging streamside vegetation.
Finally, before we embrace wholeheartedly the current thinking on riparian buffers, government fish biologists need to be reminded that twenty years ago their "best available science" required the timber industry to pull out woody debris from the streams. Years later they discovered their "best science" was wrong. Now, the timber industry spends hundreds of thousands of dollars replacing woody debris. Instead of setting standards and rushing in to implement them, the better idea is to remain flexible in our approaches. Let's give innovative ideas a chance to work, monitor the practices for results, and then adopt those ideas that obtain the best results, rather than rushing to impose unreasonable standards on family farms and possibly forcing them out of business.
Linda M. Johnson is Director of Government
Relations for the Washington State Farm Bureau. She can be reached
at ljohnson@wsfb.com or (360) 357-9975, ext. 15.
|
AENews Submission PolicyAgrichemical & Environmental
News welcomes viewpoints that
oppose or differ from articles presented in this and other issues.
All contributions must relate to agrichemicals and their related
environmental and human health effects, and must be timely, well
written, and appropriate for the target audience of AENews. Those
interested in submitting an article may contact these members
of the WSU Food & Environmental Quality Lab staff to discuss
the applicability of their ideas before submitting. |
Pick up any daily newspaper in the Northwest, and you will read at least one or two stories about the plight of the salmon. Salmon is a great symbol of the Northwest's proud cultural heritage and bountiful natural resources. But a kind of gloom spreads across this pride like the dark skies of the coastal Northwest's infamous winters. The diminishing runs of salmon in certain Pacific Northwest rivers and the multiple millions of dollars spent for technological fixes have become metaphors for all that ails modern society. And now the hapless salmon has become a political pawn as opinions diverge about what actions should be taken to preserve its runs in the major tributaries of the Columbia River.
The reasons for declining runs of salmon have spread over the years like slime molds on the wet side of the Cascades. To the list of typical factors-dams, climate change, overfishing, and predators-comes the most recent explanation, pesticides. The recently released report, Diminishing Returns: Salmon Decline and Pesticides (4), proffers the idea that "there is a plausible basis for considering pesticides as a causative factor in salmon population declines." The report's author, a former physiologist and hatchery specialist with the Oregon Department of Fish and Wildlife, reaches this conclusion after reviewing the scientific literature on the sublethal effects of pesticides on fish.
Noting sponsorship from the Oregon Pesticide Education Network, some have criticized this report and its timing as a political ploy for a bill wending its way through the Oregon State Legislature. If passed the bill would mandate complete and routine pesticide use reporting to the state by all private and commercial applicators.
Whether
Diminishing Returns was politically
motivated is irrelevant to the issues the report has raised. The
report is a literature review and analysis that has put forth
a hypothesis. The hypothesis should stand on its own merits or
fall because it is flawed. Scrutiny of the hypothesis is therefore
required, and fortunately, one can critically read the same literature
cited in support of the report's conclusions.
While addressing every point made by Diminishing Returns is beyond the scope of this essay, close examination of how its conclusions were reached indicates a problem common among environmental advocacy groups that review the toxicological literature. In short, the report failed to account for the doses used in the various studies and to cross reference the actual environmental levels of pesticides to which fish are likely to be exposed.
To make a case that pesticides might be a "causative factor" in decimating salmon populations, one has to show that pesticides are prevalent where the fish roam. Thus, Diminishing Returns uses the abundance of pesticide monitoring data from the U.S. Geological Survey National Water-Quality Assessment Program (NAWQA ). Examining five major basins in the Northwest and California, the report shows how many pesticides were examined, how many were detected, and the number exceeding aquatic life criteria.
Promulgated by regulatory agencies, the aquatic life criteria are concentration guidelines, not enforceable standards, aimed to protect the most sensitive species. Diminishing Returns emphasized that many pesticides do not yet have established aquatic criteria, but did not bother to report any concentrations in the NAWQA database.
Diminishing Returns divided the adverse effects of pesticides on salmon species into acute toxicity and sublethal effects. Large fish kills (acute toxicity) are periodically noted, especially following runoff of certain insecticides immediately after application. As noted in the report, however, acute fish kills are infrequent. Instead, Diminishing Returns states, "pesticide contamination at sublethal levels are [sic] probably an even greater danger to salmonid populations because the contamination is poorly regulated, the mortalities go unseen, and the consequences are unknown."
Delineated sublethal effects included the following:
Diminishing Returns briefly described each adverse effect by citing studies with specific pesticides, especially if observed in any of the salmon species (which includes the trout). Many of the examples were of pesticides either no longer used or not detected in the western river basins. When data for specific pesticides were not available, adverse effects known from exposures to other industrial chemicals or by-products (e.g., PCBs, dioxins, nonyl phenol) were cited as surrogates. In the case of possible effects on the male endocrine system, studies with mammals were used to speculate possible effects on fish.
Diminishing Returns presented a table showing forty-nine pesticides detected in the various Northwest river basins. It lamented the fact that less than half of these pesticides have been assigned aquatic life criteria. But does that really matter? More important is: (1) assessing the probability that salmon might be exposed and (2) determining the actual environmental concentrations of the pesticides present. The probability of exposure can be estimated from the NAWQA data for each basin by examining the percentage of total water samples collected showing a positive detection. Assuming that we might want to be concerned about any fish having a greater than one in ten chance (i.e., a 10% probability) of being exposed to any one pesticide, I tabulated pesticide detection frequencies 10% or greater in each of the NAWQA basins relevant to salmon habitat. In other words, I focused on pesticides that were found in at least one out of every ten water samples analyzed.
Several trends emerged to show that western river fish are more frequently exposed to herbicides than insecticides. Twenty herbicides were detected with frequencies of at least 10%, but only three (atrazine, simazine, and diuron) were observed in more than half of the water samples. Eleven insecticides were detected at a frequency of at least 10%, but only chlorpyrifos and diazinon in the San Joaquin-Tulare Basin were detected in more than half of the samples (Table 1). At low parts per billion (ppb) concentrations, insecticides are significantly more hazardous to fish (both acutely and via sublethal effects) than herbicides, so their detections are worth focusing on.
Insecticide detection frequencies clearly showed that the probability of exposures is comparatively low in the Central Columbia Plateau and Willamette basins. In the Central Columbia Basin, slightly more than one in ten water samples showed insecticide presence. Frequency of detection was higher in the Willamette Basin, where up to one in three samples contained carbofuran or diazinon. The greater frequency in the San Joaquin-Tulare Basin reflects agricultural practices which include winter dormant spraying and its subsequent runoff.
Pesticide detection frequencies define the potential for exposure, but they are not indicative of hazard. Like a broken record, I will repeat what toxicologists observe in every experiment where a range of doses are used to examine physiological effects. The magnitude of the effect is directly related to the exposure dose.
The relationship between dose (or concentration)
and response is characterized by exposing a group of test organisms
to a range of doses. The specific responses could range from simple
changes in enzyme activities or behavior to outright mortality.
When death is the toxicological endpoint of interest, the experimenter
can calculate the LC50, defined as "lethal concentration
to 50% of the organisms." If behavior is the endpoint, the
effective concentrationcausing a response in 50% of the organisms,
or EC50, is used.
Based on many studies with insecticides that have a specific mode of toxic action, it is known that susceptible populations respond to a fairly narrow range of doses. Whether the measured response is enzyme activity, behavior, or death, there are doses that cause no effect at all. Assessing the risk of an adverse effect requires a critical examination of the effective dose in relation to the actual exposure.
Diminishing Returns claims that sublethal effects at concentrations significantly lower than the LC50 are responsible for adversely affecting fish populations. Close examination of the literature used to support these conclusions revealed that for the majority of the adverse effects reported, the concentrations tested were in fact a substantially large percentage of the LC50 (Table 2). For example, the schooling behavior of juvenile fathead minnows was altered by exposure to a sublethal chlorpyrifos concentration of 47 ppb. The LC50 of chlorpyrifos is 203 ppb. Thus, the effective concentration tested was about 20% of the LC50, which is not a low concentration as claimed in Diminishing Returns. With the exception of carbaryl, the tested concentrations of other pesticides having a direct effect on fish behavior or development were near the level of the LC50. Fish exposed to concentrations within a factor of ten of the LC50 (i.e., 10% or more of the LC50), may not die, but they can still become sick and behave erratically without exhibiting visible changes in appearance.
TABLE 2
|
||||||
Pesticide |
Effect |
Fish Species (age) |
Effective Concentration |
LC50 |
95* |
Ref. |
| chlorpyrifos | Impaired swimming | Rainbow Trout (juveniles) | 5 | 8 | 0.026 | 7 |
| permethrin | Impaired swimming | Rainbow
Trout (juveniles) |
7 | 7 | <0.010 | 7 |
| 2,4-DBE | Impaired swimming | Rainbow
Trout (yearlings) |
2000 | ~9000 | <0.15** | 2 |
| 2,4-DBE | Increased predation | Sockeye
Salmon (fry & smolts) |
700 | <1000 | <0.15** | 10 |
| carbaryl | Increased predation | Rainbow
Trout (0.5 1 gram) |
10 | 1950 | 0.064 | 9 |
| chlorpyrifos | Schooling behavior | Fathead
Minnow (juveniles) |
47 | 203 | 0.026 | 7 |
| permethrin | Schooling behavior | Fathead
Minnow (juveniles) |
7.2 | 15.6 | <0.010 | 7 |
| trifluralin | Skeletal deformities | Atlantic
Salmon (fry to adults) |
250 | 210*** | 0.011 | 13 |
| atrazine | Habitat modification | Blue
Gill (fry to adults) |
20 | 42,000 | 2 | 8 |
|
*95th percentile concentrations from NAWQA database, http://water.wr.usgs.gov/pnsp/allsum/. **Reported as 2,4-D, the likely degradation product of 2,4-DBE. ***Based on Rainbow Trout. |
||||||
Compared to residue levels actually found in the environment, the concentrations tested were unrealistically high. This comparison is shown in Table 2, which also gives the 95th percentile figure for residue concentration as reported by the NAWQA. For example, the 95th percentile concentration for carbaryl is 0.064 ppb, meaning that 95% of all carbaryl residues detected were less than this value. Thus, even though the concentration of carbaryl associated with a sublethal effect (10 ppb) was only 0.5% of the LC50 value (i.e., 1950 ppb), the tested concentration was over 150 times greater than nearly all of the carbaryl residues found in water throughout the United States. Thus, the probability of fish being exposed to toxic-even sublethally toxic-levels of carbaryl is extremely low.
A frequent complaint associated with pesticide residue statistics is lack of aquatic life criteria for judging their biological significance. Such concerns are voiced because exceedance of the criteria has been interpreted as possibly resulting in unacceptable adverse effects on aquatic organisms (11). These concerns may be overstated for two reasons. First, the most hazardous pesticides are the insecticides, and most detected at greater than 10% frequency actually do have established criteria (Table 1). More importantly, of all the pesticides detected, exceedance of the criteria is quite infrequent, occurring only for a handful of chemicals in less than 5% of all water samples (Table 3). The second reason that concern is unwarranted comes after consideration of the current knowledge of ecosystem-level effects of the most prevalently detected insecticides, chlorpyrifos and diazinon.
TABLE 3
|
|||
Pesticide |
Central Columbia |
Willamette |
San Joaquin-Tulare |
| atrazine | 1.9 | ||
| azinphos-methyl | 12 | 1.4 | 15.8 |
| carbaryl | 7.9 | 9.6 | |
| carbofuran | 1.4 | ||
| chlorpyrifos | 4 | 1.9 | 10.3 |
| DDE | 2.8 | 22.6 | |
| diazinon | <1 | 30.7 | 64.4 |
| diuron | 11.2 | 0.6 | |
| lindane | <1 | 0.1 | |
| malathion | 0.5 | 0.6 | |
| parathion | <1 | ||
| triallate | 3 | ||
| trifluralin | 0.6 | ||
Ultimately, the ecological risk of pesticides in water must be judged from the perspective of disruption of the ecosystem. From this perspective, any one population becomes less important than the stability of the entire system. While no comprehensive long-term field studies exist to answer questions about ecosystem- level effects, shorter-term ecosystem studies known as mesocosms have been conducted with the insecticides diazinon and chlorpyrifos.
In mesocosm studies, a diversity of aquatic plant, invertebrate and fish species are allowed to establish in large-scale ponds or ditch-like structures. Because the structures are replicated, multiple concentrations of pesticides can be applied to determine a concentration causing no overall effect on the model ecosystem through several life cycles of the resident species. Tests with chlorpyrifos indicate no effects on aquatic invertebrates or fish when concentrations are less than 0.1 ppb (6). Even at 0.2 ppb, invertebrates recover to "normal" levels within several weeks after initial exposure. Mesocosm studies with diazinon show no effects at levels of 2 ppb or less (5). According to the NAWQA database, 95% of all chlorpyrifos and diazinon detections are less than 0.026 and 0.13 ppb, respectively. Thus, experimental studies indicate that even for ecosystem-level effects, the residues in the environment are below levels of biological concern.
Because atrazine herbicide is the most frequently detected pesticide, much attention has been given to studying its ecological effects. A study noted in Table 2 indicated that atrazine phytotoxicity could alter vegetative cover and thereby reduce the availability of invertebrate food for fish. The likelihood of such a significant ecological effect occurring in rivers is extremely remote. The study mentioned was conducted in a closed-system pond, whereas rivers have freely moving water. Furthermore, the vast majority of detections of atrazine in the Northwest are at levels hundreds of times lower than those known to affect aquatic vegetation. Finally, a comprehensive assessment of the ecological risk of atrazine residues in North America concluded that it is safely below any levels of concern (12).
Diminishing Returns claims that pesticide residues are a plausible cause of salmon population declines by virtue of noted sublethal effects at concentrations not acutely toxic (i.e., below the LC50). Critical examination of the evidence presented in support of this hypothesis revealed that the concentrations associated with sublethal effects are quite high when viewed as a percentage of the LC50. Furthermore, the concentrations reportedly causing sublethal effects were almost always hundreds to thousands of times greater than the actual concentrations present in the environment.
The probability that pesticide residues in the Northwest have adversely affected salmon populations just doesn't seem to hold water given that concentrations are nearly always detected substantially below one part per billion. Compared to the myriad ways humans can reportedly decimate salmon populations, blaming pesticides may be the biggest red herring of them all.
|
Food Safety
|
The Washington State Department of Agriculture
(WSDA) has maintained a Farmworker Education Program since 1990.
The program's goal is to protect Hispanic pesticide users and
agricultural workers from hazardous exposure to pesticides. Through
pesticide safety, pre-license classes, and other outreach activities,
over twelve thousand farmworkers have been taught how to work
safely around pesticides and their residues. The Farmworker Education
Program has translated a Washington State University (WSU) pesticide
safety video into Spanish, held regular radio call-in shows on
pesticide safety and education, published a Spanish version of
the WSDA newsletter (Pesticide Notes), held hands-on applicator
training, and recently completed work with WSU to translate the
Private Applicator study guide into Spanish.
The program's success has resulted in challenges. With a growing demand for pesticide safety classes given in Spanish, every class is filled to capacity. One fulltime, bilingual training specialist and one clerical support person have performed most of the work outlined above. An added concern is that many individuals come to the Spanish-language pre-license classes ill prepared and lacking basic skills not only in English, but in Spanish as well.
To face these challenges, WSDA turned to the agricultural community in 1997, conducting four statewide focus groups. In these sessions, growers, foremen, trainers, and other participants gave their opinions and advice regarding WSDA's Farmworker Education Program. The focus groups expressed overwhelming support for the goals and achievements of the program, but also made it clear that much more needs to be done. A more comprehensive and cooperative approach to providing pesticide safety training to Hispanic farmworkers was recommended.
To further explore the issues raised, WSDA set out to understand the educational needs of Hispanic farmworkers in Washington, to learn effective training methods, and to begin pilot partnerships and educational activities to broaden the availability of Spanish-language pesticide education.
Farmworker
QuestionnaireIn 1998, WSDA administered a farmworker questionnaire in Spanish to Hispanic farmworkers. The survey focused on three areas: the lower pass rate on the Spanish Private Applicator exam; topic areas for Spanish recertification courses; and impediments to job advancement for Hispanic farmworkers. Over 250 completed questionnaires were returned.
Comments included the top three problems or difficulties encountered when taking the Spanish language Private Applicator exam. They were:
When asked, "What do you think are the most important things for you to study or learn to be able to do your job better or get a better job?" the great majority responded, "ENGLISH." Respondents also reported that the top three recertification topics in which they are most interested are "pesticide safety," "labels," and "use of non-chemical means of control."
To better address the needs expressed by the workers, WSDA has developed a 1-1/2-hour pre-license orientation class. WSDA has also worked with WSU to translate the Private Applicator manual into Spanish, revised both the English and Spanish language Private Applicator exam and partnered with the agricultural community to increase training programs for Hispanic handlers and applicators.
The Spanish-language pre-license orientation
course provides participants with a realistic picture of the skills
required to be successful on the Private Applicator exam. It also
informs participants where to go if they need extra help in developing
their skills. These classes, implemented this past winter, are
being well received by participants.
Jorge Lobos, WSDA's Farmworker Education Specialist, has been working diligently to partner with agricultural associations and educators to increase the number of Spanish language recertification courses. Even as the number of Hispanic Private Applicators increases, there is a tremendous shortage of continuing education courses in Spanish. WSDA hopes to identify and work with licensed Hispanic applicators to assist them in becoming recertification instructors.
Lisa Drittenbas and Tim Stock, WSDA Farmworker Education Program Staff in the Wenatchee area, have also been working to increase the availability of Spanish language pesticide safety training with a focus on the unlicensed pesticide handler/applicator. Research has shown this group to be particularly vulnerable to work-related pesticide exposure.
In exploring various training programs from other parts of the country, WSDA has learned that hands-on, interactive workshops are the most effective for teaching pesticide safety. "Learning by doing" results in a higher level of comprehension and retention than traditional classroom-style training methods. WSDA is exploring the use of these types of programs. It recently partnered with the agricultural community in Wenatchee to sponsor a hands-on training program for pesticide handlers (see related article following).
In order to work more cooperatively with the farming community, a Farmworker Education Advisory Committee was formed. The committee meets regularly in Wenatchee. Participants include foremen, crop advisors, farmers, WSU extension agents, trainers, and other industry representatives. At the meetings, members share and discuss ideas and initiatives, as well as ways to collaborate their efforts. Anyone interested in farmworker education is encouraged to join. Topics discussed have included:
WSDA plans to continue working with the committee and other interested partners to encourage local support for training initiatives. The committee hopes that their efforts will encourage other communities to work together to improve the pesticide safety training opportunities for Hispanic farmworkers.
If you would like more information
about WSDA's Farmworker Education Program, or would like to become
involved with the Farmworker Education Advisory Committee, please
call Lisa Drittenbas in Wenatchee at (509) 665-3395, or Margaret
Tucker in Olympia at (360) 902-2015.
A bilingual pesticide applicator training class received high marks from those taking the two-day class at Wenatchee Valley College in March. With an emphasis on the latest pesticide regulations and safety for workers and the environment, the class attracted thirty-three Spanish-speaking and eight English-speaking persons.
The March 12 event was co-sponsored by the Washington State Department of Agriculture, Washington State Horticultural Association, Wenatchee Valley College, and WSU Cooperative Extension.
The training was modeled after a program
developed by the University of California, Davis. Coordinators
hope to use this class as a pilot program for a larger event,
possibly to take place in July at the Chelan County fairgrounds.
In the hands-on workshops, participants worked in groups of ten to twelve people and rotated through four stations: First Aid, Personal Protective Equipment, Mixing and Loading, and Clean-up and Disposal. Each group was led by two bilingual, volunteer trainers using a "learning by doing" approach. Volunteer trainers, experienced in their fields, came from Wenatchee, Cashmere, Orondo, Ephrata, Pasco, Yakima, Royal City, and Vantage.
Comments from the participants included:
"Very useful. I hope they continue with this method (of teaching)," and
"with this type of training you learn to do a better job and more skillfully.''
When asked, "What did you learn that will make you a better pesticide handler?" responses included:
"I learned that pesticides should be treated with care and caution, not fear,"
"I learned how to be better protected and prepared to train other people," and
"(I learned) the latest regulations. It refreshed me on a lot of little details that we tend to forget or overlook."
The idea for the small-scale workshops in Washington was developed by members of a Farmworker Education Advisory Committee organized in 1997. Committee members include growers, managers, fieldmen, educators, and others who have an interest in farmworker safety and education. If you are interested in becoming a member of this Committee, would like more information about hands-on training or becoming a volunteer trainer, please call Lisa Drittenbas at (509) 665-3395 or Tim Stock at (509) 662-0590.
Providing health education and farm safety training to Hispanic farm workers in the Lower Columbia Basin, Yakima Valley, and Walla Walla areas is the objective of a pilot project funded by the Pacific Northwest Agricultural Safety and Health Center. The pilot program is being conducted by the Center for Farm Health and Safety at Eastern Washington University and is being coordinated by Kathy Pitts, an EWU sociologist.
Community-based theater was selected as a method of providing basic farm health and safety information to the target population. Theater does not require a high level of literacy and is effective in providing information to a group with varying levels of language and literacy skills. The information will be provided in four one-act plays, written and presented in Spanish, each of which addresses several learning objectives.
An integral part of each play will be telling play-goers where they can go to get more information and help, and what kind of information they will need to provide in order to access the resources.
During the first year of the project, a series of focus groups identified the most urgent health and safety needs of Hispanic farm workers and their families. This information is being used to develop the four one-act plays.
EWU staff have developed working relationships
with the Yakima Valley Farm Workers Clinic and the Special Populations
Department at Walla Walla Community College. The regional health
districts and migrant Headstart offices in Benton, Franklin, Walla
Walla and Yakima counties have also assisted in developing the
project.
At the completion of the pilot program, community groups will
receive four pre-tested plays and a method of organizing community
members and aiding them in the production of each play or program.
Local communities will collaborate with Pitts and other EWU researchers
to produce four plays in a "fiesta" atmosphere. Growers
are being asked to donate food, churches will prepare food, and
Latino entertainment groups will perform at each play production.
The Pacific Northwest Agricultural Safety and Health Center, funded by NIOSH, is one of eight such centers in the United States. The Center's mandate is to study occupational health and safety issues in farming, forestry, and fishing in the four Region X states of Idaho, Washington, Oregon, and Alaska. Dr. Richard Fenske is the Center Director, Dr. Matthew Keifer is Co-Director, and Sharon Morris is Associate Director. Adrienne Hidy is the Center's Administrator, and Marcy White is the Program Coordinator.
The Center for Farm Health and Safety is housed in the Department of Sociology at Eastern Washington University. The Center's director is Dr. Pam Elkind. Other center researchers are Dr. Steve Neufeld, and Dr. Sue Wright. C.J. Tyler-Watson is the Center's outreach program coordinator.
This article was prepared by Norm Herdrich, PNASH Outreach Coordinator. To obtain additional information, contact him at (509) 926-1704 or normh@u.washington.edu.
I recently overheard the following question:
If a pesticide contains, as its sole active ingredient, a compound identified as being exempt from the requirement for a tolerance, why can't the product be applied to any crop regardless of the label use directions?
The answer--in the short form--is reminiscent of that age-old paternal response "because I said so." While no one likes to be told that she has to do something simply because the regulations require it, in truth this really is the answer, the whole answer, and nothing but the answer.
The Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) as well as Washington State regulations contain language about following the label use directions. FIFRA Section 12(a)2 states "It shall be unlawful for any personto use any registered pesticide in a manner inconsistent with its labeling...." This language is mirrored in the Washington Pesticide Control Act where RCW 15.58.150(2)(c) states "It shall be unlawfulfor any person to use...any pesticide contrary to label directions...."
So, yes, the regulations stipulate that
you must follow the label use directions.
If label compliance is so clear and basic (some of the logic behind the edict follows later), it begs a corollary question: Which products are required to have a label?
One might reasonably conclude that if an ingredient were so innocuous as to be exempt from the requirement for a tolerance (defined as "a legally allowable pesticide residue") that it shouldn't need to be registered in the first place and thus wouldn't have a label (and directions) to worry about. But being exempt from the requirement for a tolerance doesn't relate to the requirement that a product be registered. The answers lie in the governing authorities' definition of "pesticide."
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The Letter of the Law
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The fact is, the Environmental Protection Agency (EPA) has exempted some ingredients from the requirement for registration. These are listed in Section 25(b) of FIFRA and include items such as garlic oil, dried blood, mint and mint oil, white pepper, cloves and clove oil, and putrescent whole egg solids. But EPA's perspective isn't shared by Washington Department of Agriculture (WSDA). In Washington, such products must be registered-they are "federally exempt," but not exempt from registration in the state of Washington.
The Spirit
of the LawThe question posed above implies, in its reference to tolerances, that the main concern with pesticide use is in avoiding illegal residues on food or feed. In reality, there's more to safe pesticide use than residues. The underlying premise behind following labels is: "If it hasn't been tested, how can we call it safe?"
According to Joel Kangiser of WSDA's Pesticide Management Division, EPA studies the use patterns described on proposed product labels to determine if registration shall be granted. Their registration review process revolves around whether use per the label directions will (or won't) be protective of human health and the environment. If a pesticide, exempt ingredient or not, is used in a manner inconsistent with label directions, such use may pose a threat to human health or the environment because this use was not considered when EPA performed its review.
Here in Washington State, the group responsible for enforcing label direction adherence is the Compliance Branch of WSDA's Pesticide Management Division. Provisions also exist for EPA involvement, but the vast majority of pesticide-related compliance investigations in Washington are conducted and concluded by WSDA.
Cliff Weed, manager of WSDA's Compliance Branch, explained that, typically, WSDA will issue a "Notice of Correction" to first-time offenders in pesticide cases. The Notice of Correction tells the violator what he needs to do, when it must be done, and why.
Less frequently, WSDA will move directly to a civil penalty. These are cases where
For pesticide-related violations, WSDA employs a penalty matrix to determine the amount of any fines issued. State laws allow WSDA to levy penalties up to $7,500 per violation. Cliff Weed points out that cases resulting in civil penalties will often involve more than one violation. Of the cases investigated each year, about a third end with some type of action: either a Notice of Correction or a penalty. At this point, the majority result in the issuance of a Notice of Correction. Criminal penalties may also be levied; however, this is very rare. A case of sufficient gravity to merit criminal prosecution likely would be turned over to EPA.
How does WSDA know if something has been applied in accordance with label use directions? Often, such information comes from the records that applicators are required to keep. These records are reviewed in the process of conducting an investigation and they may show something like an application rate of one quart per acre when the label calls for one pint. Statements taken from the parties involved in an incident can also provide documentation of an illegal application. Application to the wrong crop is often picked up because of phytotoxic effects. Finally, residue testing may reveal that a pesticide has been misapplied or has drifted onto a crop for which it is not labeled.
Actually, there are several:
Jane M. Thomas is the Pesticide Notification Network (PNN) Coordinator for the Pesticide Information Center (PIC) at WSU. For rigorous intellectual discourse, call (509) 372-7493 or e-mail jmthomas@tricity.wsu.edu.
Dear Aggie:
Lately we hear nothing but "tolerances," "residues," and "food safety." I'm getting a bit tired of it. What's the fuss? As all responsible growers know, if you follow label use directions, you are guaranteed that the crop you produce will be below the tolerance.
Just sign me,
Legal Beagle
Dear Beagle:
Well, sort of--but let's not bark up the wrong tree. Dr. Carol Weisskopf has an interesting story from her days in "sunny" California. In the early 1980s, Dr. W was involved in alfalfa hay sampling and testing for guthion residues. Because of an unusually cold spring, the alfalfa grew more slowly, resulting in a lower dilution, less photodegradation, less thermal degradation, and less volitalization of the guthion. Growers all over the state ended up with hay exceeding the tolerance for guthion residue.
Washington Pest Consultants Association organizes an annual series of collection dates and sites for empty pesticide containers. Dates and locations are subject to change; confirm with a telephone call to the number listed in the table before participating. For general questions, or if you are interested in hosting an event at your farm, business, or in a central location in your area, contact Clarke Brown at (509) 965-6809 or Roger Ours at (509) 930-6950.
CONTAINERS MUST MEET THE FOLLOWING CRITERIA:
DATE |
TIME |
LOCATION |
CONTACT |
PHONE# |
OTHER |
Western Washington - MAY |
|||||
| 5/11 | 8 am to Noon | Skagit Co. Transfer Station, Mt. Vernon | Robin LaRue | 360-336-9400 | Containers can be dropped off starting 4/26 except Sat/Sunday |
| 1pm to 3 pm | Tronsdal Air Service | Kevin Tronsdal | 360-757-0333 | Entrance Farm to Market Rd. | |
| 5/12 | 8 am to Noon | Port Orchard - Olympic View | Niels Nicolaisen | 360-337-5781 | Ind'l Park, 5551 SW Imperial Way |
| 5/13 | 8 am to Noon | WA State DOT & Permit Office | Randy Knutson | 253-351-6591 | 11211 - 41st Ave. SW, Tacoma |
| Dave Patterson | 253-589-7255 | ||||
| 5/14 | 8 am to Noon | Centralia Transfer Station | John Prigmore | 360-740-1193 | 1411 South Tower |
Eastern Washington - MAY |
|||||
| 5/17 | 9 am to 3 pm | Snipes Mtn, Transfer Station | Mark Nedrow | 509-574-2472 | Cardboard Accepted |
| 5/18 | 8:30 am to 3 pm | Terrace Hts. Landfill, Yakima | Mark Nedrow | 509-574-2472 | Cardboard Accepted |
| 5/19 | 8 am to 12:30 am | Wilbur Ellis, Eltopia | Vern Record | 509-297-4291 | |
| 1 pm to 2:30 pm | Eastern WA Spray, Eltopia | Willis Maxson | 509-297-4387 | ||
| 3 pm to Finish | Air Trac, Pasco | Gerald Titus | 509-547-5301 | ||
| 5/20 | 8 am to 1pm | Pfister Crop Care, Pasco | Steve Pfister | 509-297-4304 | |
| 1pm to Finish | B & R Crop Care, Connell | Chris Eskildsen | 509-234-7791 | ||
| 5/21 | 8 am to 10 am | Broetje's Orchard, Prescott | Joe Shelton | 509-749-2217 | 509-537-4820 |
| Flat Top Ranch, Prescott | Dave Hovde | 509-547-9682 | |||
| 11 am to Finish | Agri Northwest, Prescott | Shawn Edler | 509-547-8870 | 509-947-1144 Cell | |
| 5/24 | 8 am to 12 pm | McGregor's, Walla Walla | Gary Burt | 509-529-6787 | |
| 1pm to 2 pm | McGregor's Waitsburg | Terry Jacoy | 509-297-4296 | ||
| 5/25 | 8 am to 10 am | McGregor's Dayton | Jim Lemon | 509-397-4355 | |
| 11am to 2 pm | Western Farm Service, Pomeroy | Jerry Wilsey | 509-843-3491 | ||
| 5/26 | 8 am to 10 am | McGregor's Pullman | Larry Schlenker | 509-332-2551 | |
| 11am to Finish | McGregor's Colfax | Joel Fields | 509-397-4691 | ||
| 5/27 | 8 am to 10 am | McGregor's Palouse | Mike Dial | 509-878-1321 | |
| 11am to 1 pm | Cascade Flying Service, Garfield | Doran Rogers | 509-635-1212 | ||
| 2 pm to Finish | Dusty Farm Co-Op, Inc. Dusty | John Stoner | 509-397-3111 | ||
DATE |
TIME |
LOCATION |
CONTACT |
PHONE# |
OTHER |
Eastern Washington - JUNE |
|||||
| 6/1 | 8 am to 12 am | Wilbur Ellis, Quincy | Dale Martin | 509-787-4433 | |
| 1pm to 2 pm | Quincy Flying Service | Richard Weaver | 509-787-3223 | ||
| 3 pm to Finish | The Crop Duster, Ephrata | Martin Shaw | 509-754-3461 | ||
| 6/2 | 8 am to 10 am | Cenex, Almira | Scott Winona | 509-632-5645 | 509-641-0611 Cell |
| 11 am to 2 pm | Wilbur Airport | Greg Leyva | 509-647-2441 | ||
| Dennis Buddrius | 509-647-5394 | ||||
| 3 pm to Finish | Davenport Airport | Lee Swain | 509-725-0011 | ||
| 6/3 | 8 am to 10 am | Westerm Farm Serv. Davenport | John Massey | 509-838-5007 | |
| 11 am to 1 pm | Westerm Farm Serv.Harrington | Jim Hurst | 509-253-4311 | ||
| 2 pm to 4 pm | Grange Supply Cenex, Odessa | Greg Luiten | 509-982-2693 | ||
| 6/4 | 8 am to 10 am | Grange Supply Cenex, Ritzville | Dale Anderson | 509-659-1360 | |
| 11 am to 1 pm | Rudy's Aviation, Lind | Rudy Fichtenberg | 509-677-8858 | ||
| 6/7 | 8 am to10 am | Wilbur-Ellis, Mattawa | Al Hilliker | 509-932-4988 | |
| Tammy Merkle | 509-932-4988 | ||||
| 11 am to 1 pm | Cenex, Bruce Dealers, Othello | Lori Anderson | 509-488-5261 | ||
| 2 pm to 3 pm | B & R Ag. Chemical, Othello | Larry Hawley | 509-488-6576 | ||
| 6/8 | 8 am to 1 pm | Othello Airport, Ohello | Mark Conner | 509-488-2921 | |
| 2pm to Finish | D & S Crop Car | ||||