Illinois Pesticide Review
May / June 2014
In This Issue
- Identify Pests Before You Treat Them
- Terbufos and Prostate Cancer
- Pesticide Poisoning May Increase Risk of Depression
- Maintaining Personal Protective Equipment
- EPA Extends Comment Period for Proposed New Safety Measures to Protect Farm Workers from Pesticide Exposure
- How Are You Measuring Up? Part 2: Dry Formulations
Identify Pests Before You Treat Them
Publications from University of Illinois specialists can help you identify pests.
Correct pest identification is the first step in developing a successful Integrated Pest Management (IPM) plan. Not all weed, insect, or disease damage is clear-cut. When you throw in the abiotic/non-pathogenic problems such as chemical drift, drought, lightning, soil compaction, etc., with the true bugs, fungi and weeds it can become mind-boggling. Who would have thought that chemical injury can look like leafhopper injury? It can.
Sometimes it's difficult to identify the problem. Insects may be nocturnal, working when we don't see them. Problems may show up long after the pest is there. One man's weed may be another's ideal plant. Pathogenic diseases are usually microscopic and difficult to see.
A magnifying glass or hand lens is great for identifying some insects and diseases. Sometimes you need to shake a piece of the plant over black or white cardboard and see if anything moves.
Field guides are numerous. Check out bookstores, or look for resources from the University of Illinois specialists at pubsplus.illinois.edu. Newer apps for cell phones and tablets are available for quick ID, though none comes close to being perfect at the moment.
Once the pest has been identified, solutions are easier to develop, starting with cultural, mechanical and biological control options before heading for the chemical container.
Many local University of Illinois Extension offices have educators or Master Gardeners who can assist with pest identification. Extension offices also have access to the University of Illinois' DDDI (Distance Diagnostics through Digital Imaging) system, which can send images to specialists throughout the state and on campus. Turn-around is usually less than 48 hours.
There are many University of Illinois Extension and state websites that can assist, including the following:
• Turfgrass Pests: http://urbanext.illinois.edu/turf/
• General Insects: http://urbanext.illinois.edu/bugreview/
• Vegetable Problems: http://urbanext.illinois.edu/vegproblems/vegetables.html
• Wildlife Problems: http://web.extension.illinois.edu/wildlife/
• General Plant Problems: http://urbanext.illinois.edu/focus/
• Environmental Health Problems (mosquitoes, bedbugs, cockroaches, etc.): http://www.idph.state.il.us/envhealth/entpestfshts.htm
Terbufos and Prostate Cancer
Smartboxes may help reduce the risk of pesticide exposure.
Other than certain skin cancers, prostate cancer is the most common cancer in men in the United States. Farmers are more likely than other men to develop prostate cancer. In 2003, Agricultural Health Study researchers reported an association between some pesticides and prostate cancer among those with a family history of prostate cancer.
The Agricultural Health Study (AHS) is a federally funded program studying the long term health effects of farming and other agricultural-related activities. Since 1993, it has been following the activities, habits, and health of 89,000 farmers, ag professionals, and their families in North Carolina and Iowa.
In 2013 they completed an analysis of 2,000 men in the study who have developed prostate cancer. While they found some evidence of an association between some pesticides and prostate cancer overall, the strongest evidence was for a link between a few specific insecticides and a subtype of prostate cancer that is fast-growing or aggressive.
This finding was based on information from AHS participants who answered questions about their lifetime use of 50 different pesticides when they enrolled in the study between 1993 and 1997 and then again 5 years later. Dr. Stella Koutros of the National Cancer Institute in Rockville, Maryland, and her colleagues found that frequent users of the insecticides malathion and terbufos were more likely to develop aggressive prostate cancer, compared with participants who didn't use either insecticide. Fonofos and aldrin, insecticides that are no longer registered for use in the U.S., were also associated with an increased risk of aggressive prostate cancer.
Terbufos is sold as Counter for corn rootworm control and is used heavily in Illinois. In recent years, Lock'N Load, Smartbox, and other mechanisms have been promoted by the manufacturer to reduce the exposure to this highly toxic insecticide. These advancements in applicator protection have probably reduced the likelihood of applicators developing cancer.
Malathion continues to be used in a variety of situations. Compared to most other insecticides, it is shorter-lived and has a lower acute toxicity to humans. Fonofos was marketed as Dyfonate and other trade names for the control of field crop and other insect pests. Aldrin was marketed as Aldrin and was used for the control of termites, field crop pests, and various other insect pests.
This new work is important because it included a large number of men with prostate cancer and it was possible to focus specifically on aggressive prostate cancer, a more clinically significant form of the disease.
The original scientific journal article is: Koutros, S., Beane Freeman, L.E., Lubin, J.H., Heltshe, S.L., Andreotti, G., Barry, K.H., Dellavalle, C.T., Hoppin, J.A., Sandler, D.P., Lynch, C.F., Blair, A., Alavanja, M.C. (2013). Risk of Total and Aggressive Prostate Cancer and Pesticide Use in the Agricultural Health Study. American Journal of Epidemiology, 177(1):59-74.
AHS news release modified by Phil Nixon
Pesticide Poisoning May Increase Risk of Depression
Pesticide exposure may increase the risk of certain illnesses, including cancer and depression.
In the United States, about 20% of women have been diagnosed with depression, compared to about 11% of men. Some studies, including the Agricultural Health Study (AHS), have shown a link between pesticide use and depression in men. But information on the risk for women was limited. John Beard, of the University of North Carolina at Chapel Hill, and his colleagues have now completed the first follow-up study of women's pesticide exposure and risk of depression.
The investigators looked at data from almost 17,000 wives of farmers and pesticide applicators in the AHS. None of the women had depression when the study began. The women reported information on their exposure to 50 different pesticides. More than 1,000 women were diagnosed with depression during 12 years of follow-up.
The researchers found that women who used pesticides, or whose husbands used pesticides, did not have a greater risk of developing depression than the other women. However, the few women in the study who had been diagnosed by a physician with pesticide poisoning were nearly twice as likely to develop depression compared to women who had never been diagnosed with pesticide poisoning. The researchers controlled for other factors that have been linked to depression, such as having a chronic disease.
It is not yet fully understood how pesticides may affect the risk for depression. However, it is known how to decrease the likelihood of pesticide poisoning. When working with pesticides, be sure to follow the manufacturer's label instructions and use good work hygiene and personal protective equipment when needed.
The original scientific journal article is: Beard, J.D., Hoppin, J.A., Richards, M., Alavanja, M.C., Blair, A., Sandler, D.P., Kamel, F. (2013). Pesticide exposure and self-reported incident depression among wives in the Agricultural Health Study. Environ Res., 126:31-42.
AHS news release modified by Phil Nixon
Maintaining Personal Protective Equipment
Disposable latex gloves are designed to be worn only once and then thrown away.
At this time of the year, when pesticides are commonly being used, it is important to take the time to properly clean and maintain Personal Protective Equipment (PPE).
When you finish an activity in which you are handling pesticides or are exposed to them, remove your personal protective equipment right away. Start by washing the outside of your gloves with detergent and water before removing the rest of your PPE. Wash the outside of other chemical-resistant items before you remove your gloves. This practice helps you avoid contacting the contaminated part of the items while you are removing them, thus keeping the inside surface from becoming contaminated. If any other clothes have pesticides on them, change them also. Determine whether contaminated items should be disposed of or cleaned for reuse.
Disposable PPE items are not designed to be cleaned and reused. Discard them when they become contaminated with pesticides. Place disposable PPE in a separate plastic bag or container prior to disposal.
Chemical-resistant gloves, footwear, and aprons labeled as disposable are designed to be worn only once and then thrown away. These items often are made of thin vinyl, latex, or polyethylene. These inexpensive disposables may be a good choice for brief pesticide-handling activities that require dexterity, as long as the activity does not tear the thin plastic. For example, you might use disposable gloves, shoe covers, and an apron while pouring pesticide into a hopper or tank, cleaning or adjusting a nozzle, or making minor equipment adjustments.
Nonwoven (including coated nonwoven) coveralls and hoods, such as Tyvek™, usually are designed to be disposed of after use. Most are intended to be worn for only one workday. The instructions with some coated nonwoven suits and hoods permit the user to wear them more than once if each use period is short and not much pesticide gets on them. Pay close attention when reusing these items, and be ready to change them whenever there are signs pesticides could be getting through the material or the inside surface is contaminated.
Dust/mist masks, prefilters, canisters, filtering and vapor-removing cartridges, and a few cartridge respirators are disposables. They cannot be cleaned. Be sure to replace these disposable items often.
Some PPE items, such as rubber and plastic suits, gloves, boots, aprons, capes, and headgear, are designed to be cleaned and reused several times. However, do not make the mistake of continuing to use these items when they no longer offer adequate protection. Wash the reusable items thoroughly between uses, and inspect them for signs of wear or abrasion. Never wash contaminated gloves, boots, respirators, or other PPE in streams, ponds, or other bodies of water. Check for rips and leaks by using the rinse water to form a "balloon" (that is, filling the PPE item with water) and/or by holding the items up to the light. Even tiny holes or thin places can allow large quantities of pesticide to penetrate the material and reach your skin. Discard any PPE item that shows sign of wear.
Even if you do not see any signs of wear, replace reusable chemical-resistant items regularly–the ability of a chemical-resistant material to resist the pesticide decreases each time an item is worn. A good rule is to throw out gloves that have been worn for about 5 to 7 workdays. Extra-heavy-duty gloves, such as those made of butyl or nitrile rubber, may last as long as 10 to 14 days. Glove replacement is a high priority because adequate hand protection greatly reduces the pesticide handler's chance for exposure. The cost of frequently replacing your gloves is a wise investment.
Footwear, aprons, headgear, and protective suits may last longer than gloves because they generally receive less exposure to the pesticides and less abrasion from rough surfaces. Replace them regularly and at any sign of wear. Most protective eyewear and respirator bodies, face-pieces, and helmets are designed to be cleaned and reused. These items can last many years if they are of good quality and are maintained correctly.
Launder fabric coveralls and work clothing after each day's use. Do not attempt to launder clothing made of cotton, polyester, cotton blends, denim, and canvas if these items are drenched or saturated with concentrated pesticides labeled with the signal word DANGER-POISON, DANGER, or WARNING. Always discard any such contaminated clothing or footwear at a household hazardous waste collection site.
Be sure to clean all reusable PPE items between uses, even if they were worn for only a brief period of exposure. Pesticide residues that remain on PPE are likely to penetrate the material. If you wear that PPE again, pesticide may already be on the inside of the material next to your skin. Also, PPE worn several times between launderings may build up pesticide residues. The residues can reach a level that can harm you, even if you are handling pesticides that are not highly toxic. After cleaning reusable items, place them in a plastic bag or clothing hamper away from your personal clothes and away from the family laundry.
Always wash pesticide-contaminated items separately from the family laundry. Otherwise, pesticide residues may be transferred to the other laundry and may harm you or your family. Be sure that the people who clean and maintain your PPE and other work clothes know they can be harmed by touching these pesticide-contaminated items. Instruct them to wear gloves and an apron and work in a well-ventilated area, if possible, and avoid inhaling steam from the washer or dryer.
Follow the manufacturer's instructions for cleaning chemical-resistant items. If the manufacturer instructs you to clean the item but gives no detailed instructions, follow the "Procedure for Washing Contaminated PPE" detailed below. Some chemical-resistant items that are not flat, such as gloves, footwear, and coveralls, must be washed twice–once to clean the outside of the item and a second time after turning the item inside out. Some chemical-resistant items, such as heavy-duty boots and rigid hats or helmets, can be washed by hand using hot water and a heavy-duty liquid detergent.
Use the following procedure for washing non-chemical-resistant items such as cotton, cotton/polyester, denim, canvas; other absorbent materials; and most chemical-resistant items.
Procedure for Washing Contaminated PPE
1. Wash only a few items at a time so there is plenty of agitation and water for dilution.
2. Wash in a washing machine, using a laundry detergent and hot water for the wash cycle. Set your washer to the longest wash cycle and two rinse cycles.
3. Use two entire machine cycles to wash items that are moderately to heavily contaminated. (If PPE is too contaminated, bundle it in a plastic bag, label the bag, and take it to a household hazardous waste collection site.)
4. Run the washer through at least one additional entire cycle without clothing, using detergent and hot water, to clean the machine before any other laundry is washed.
5. Hang the washed items to dry, if possible. It is best to let them hang for at least 24 hours in an area with plenty of fresh air. Even after thorough washing, some items still may contain residues. When the items are exposed to clean air and sunlight, most residues move to the surface of the fabric, evaporate, or break down. You may wish to buy two or more sets of PPE so you can leave one set airing while wearing the other set. Do not hang items in enclosed living areas; pesticide residues that remain in the items may evaporate and expose people or animals in the area. If it is not possible to hang fabric items to dry, a clothes dryer may be used. Over time, however, the dryer may become contaminated with pesticide residues.
Maintaining Eyewear and Respirators
Wash goggles, face shields, shielded safety glasses, respirator bodies, and facepieces after each use. Use a detergent and hot water to wash them thoroughly. Remove any contaminants (such as residual pesticides) under running water with a soft brush. Sanitize them by soaking for at least 2 minutes in a mixture of 2 tablespoons of chlorine bleach in 1 gallon of hot water. Rinse thoroughly to remove the detergent and bleach. After rinsing to remove the detergent and bleach, dry the items thoroughly or hang them in a clean area to dry.
Pay particular attention to headbands. Replace headbands made of absorbent materials with chemical-resistant headbands. After each day of use, inspect all headbands for signs of wear or deterioration, and replace them as needed.
Store respirators and eyewear in an area where they are protected from dust, sunlight, extreme temperatures, excessive moisture, and pesticides or other chemicals. A sturdy plastic bag with a zip closure works well for storage. Store respirator cartridges in an airtight bag, or they lose their effectiveness.
Respirator maintenance is especially important. Inspect your respirator before each use. Repair or replace any part that shows signs of wear or deterioration. Maintain an inventory of replacement parts for the respirators you own, and do not use substitutes or incompatible brands. If you keep a respirator for emergency use or as a backup, inspect it at least monthly.
If you remove your respirator between handling activities, follow these guidelines:
1. Wipe the respirator body and facepiece with a clean cloth.
2. Replace caps, if available, over cartridges, canisters, and prefilters.
3. Seal the respirator (except for any prefilters) in a sturdy, airtight container, such as a plastic bag with a zip closure. If you do not seal the respirator immediately after each use, the disposable parts will have to be replaced more often because cartridges and canisters continue to collect impurities as long as they are exposed to the air.
4. Prefilters, however, do not lose their effectiveness when exposed to the air. Remove contaminated prefilters before placing the canisters and cartridges in a zip-closable plastic bag to avoid contaminating the canisters and cartridges.
At the end of every workday that you wear a reusable respirator, be sure to do the following:
1. Remove the prefilter. Most filters should be discarded.
2. Take off the cartridges or canisters. Discard them, or (if they are still usable) replace their caps and seal them in an airtight container, such as a plastic bag with a zip closure.
3. Clean and store the respirator as directed above.
Discard disposable respirators according to manufacturer's instructions. Do not try to clean them.
Remember: Do not store your respirators or other PPE in pesticide-storage areas.
Handle respirators with the same care that you give your other protective equipment and clothing. Consult labels and MSDS for instructions about protective equipment and clothing, and remember that protective equipment has limitations. A person is never completely protected and must still use caution and common sense to prevent pesticides from contacting the body.
Phil Nixon, revised slightly from the national Pesticide Applicator Core Manual.
EPA Extends Comment Period for Proposed New Safety Measures to Protect Farm Workers from Pesticide Exposure
The U.S. Environmental Protection Agency (EPA) is extending the comment period for the proposed revisions to the agricultural Worker Protection Standard for an additional 60 days, until August 18, 2014, in response to requests from growers, industry, farmworker advocates, and states for additional time to provide input.
"The opportunity to revise the rule may not come again for some time, so we are committed to getting it right," said Jim Jones, Assistant Administrator for the Office of Chemical Safety and Pollution Prevention. "Updating the 20-year-old regulation to provide more protections to the nation's two million farm workers and their families from pesticide exposure is a priority for EPA."
The proposed changes provide significant improvements to worker training regarding the safe use of pesticides, including how to prevent and effectively treat pesticide exposure. Increased training from every five years to every year and signage would help farmworkers protect themselves and their families from pesticide exposure.
Workers and others near treated fields would be better protected from pesticide overspray and fumes. In addition, the EPA has proposed that children under 16 be legally barred from handling all pesticides. These revisions protect workers while ensuring agricultural productivity and preserving the traditions of and exemptions for family members working on family farms.
To learn more and provide comments in English and Spanish:
For more information about the proposed changes, please see the March/April 2014 issue of this newsletter.
Slightly modified by Michelle Wiesbrook from an EPA email received 5/14/14.
How Are You Measuring Up? Part 2: Dry Formulations
The last newsletter included an article covering the importance of accurately measuring pesticides, focusing on the common errors that occur while measuring liquid formulations. That article was based the first part of the presentation "The Forgotten Art of Mixing and Measuring," given by Fred Whitford of Purdue University and Pat Hipkins of Virginia Tech. The second portion of their presentation discussed potential measurement errors associated with dry formulations.
For dry formulations, one measurement mistake can result from a simple confusion of units. Both liquid and dry formulations are measured in ounces. However, a liquid ounce is not the same as a dry ounce. A liquid ounce is a measure of volume, while a dry ounce is a measure of weight. Drastic changes in the application rate result from using a measuring device intended for liquids to measure a dry formulation, and vice versa.
Since dry formulations are measured by weight, they are most accurately measured with the use of a scale. A scale should always be used for applications requiring precision. Unfortunately, scales are not always readily available to applicators. For convenience, manufacturers commonly sell their products with "measuring guides" such as volumetric tubes, cups, and scoops. These guides look similar to measuring devices used for liquid formulations. However, graduations on the sides of the measuring guides correspond to dry ounces, not fluid ounces. The manufacturer customizes the measuring guide to a specific product by incrementally weighing a specific amount of the pesticide, adding it to the guide, and finally marking the guide with graduation lines that correspond to the amount of material. To help avoid confusion, all measuring devices should clearly state whether they are intended for fluid ounces or dry ounces.
Remember that measuring guides packaged with dry formulations are product-specific and are clearly labeled with the product intended to be used with. They are designed based on the volumetric weight of one specific pesticide formulation. Attempting to use a measuring guide intended for another product will almost certainly result in an incorrect amount of product being used.
Saving measuring guides is not recommended. The measuring guide should be disposed of after all of the product has been used. The volumetric weight of a product may vary between batches and changes to the formulation. Though not always evident, measuring guides may have changed from previous batches to reflect the new volumetric weight (i.e., graduations on older measuring guides may no longer be accurate).
Also, be cautious of guides packaged with closely related products that are formulated differently. For marketing purposes, the product packaging and measuring guides may look very similar. The graduations on a guide produced for the one formulation may be very different from another.
Prior to measuring the material, invert the container several times to loosen and obtain a uniform mixture of material. Avoid tapping the measuring device while measuring out the pesticide. Tapping condenses the material into the device resulting in a higher bulk density than intended by the manufacturer. This may result in higher than intended application rate.
This article was based on the presentation "The Forgotten Art of Mixing and Measuring" given by Fred Whitford of Purdue University and Pat Hipkins of Virginia Tech at the 2013 Pesticide Applicator Certification and Training Workshop. Information from the Purdue Extension Publication "Measuring Pesticides: Overlooked Steps to Getting the Correct Rate" was also used for the production of this article