December 2011 Issue
Do Organics Promote Children’s Health? — Research Shows Pesticides May Cause Neurological Disorders
By Carol Ann Brannon, MS, RD, LD
Vol. 13 No. 12 P. 34
Suggested CDR Learning Codes: 2080, 4150, 4160, 5110, 5320, 8018; Level 1
The Choose MyPlate message is concise and colorful: “Make half your plate fruits and vegetables.” While the health benefits of a diet rich in fruits and vegetables is well documented, there’s increasing concern about the safety of exposure to agricultural pesticide residues on produce, especially for pregnant women and young children.1,2 The emerging research linking pesticide exposure to childhood neurobehavioral disorders has captured parents’ attention.
As often happens, commercial promotion, hearsay, and rumors have clouded the issue and confused consumers. Dietitians should anticipate parents’ most frequently asked questions about pesticides, organic foods, and the potential link to attention, behavioral, and cognitive problems in children and offer personalized, practical, budget-friendly options for purchasing organic foods. This continuing education activity will review current studies on organophosphate (OP) pesticides and their potential to impair neurodevelopment and cause neurobehavioral disorders in children, and provide dietitians with practical tips for counseling clients.
Do Pesticides Cause ADHD in Children?
Recent studies linking ADHD and pesticide exposure have made headlines3,4 and prompted parental questions about the possible connection between children’s diets and their attention, cognition, behavior, and sensory issues as well as their overall health.
Their questions include: Is there a connection between the increased incidence of neurobehavioral disorders like ADHD and learning differences and the increased use of agricultural pesticides? How safe is conventionally grown produce for pregnant women, infants, and young children? Do the health benefits of a diet rich in conventionally grown fruits and vegetables outweigh the risks of pesticide exposure? How can organic produce be incorporated into a family’s food budget?
The percentage of children with learning and developmental disabilities (LDDs), including ADHD and autism spectrum disorder, as well as food allergies and autoimmune-related disease, has increased steadily over the past 40 years. ADHD is the most prevalent and researched pediatric psychiatric disorder, with an estimated 8.7% of U.S. children aged 8 to 15 meeting the diagnostic criteria. The fourth edition of the Diagnostic Statistical Manual of Mental Disorders of the American Psychiatric Association defines ADHD as a neurobiological disorder characterized by hyperactivity-impulsiveness and inattention or the inability to sustain attention or concentration in developmentally appropriate ways. ADHD is classified into two categories, poor sustained attention and hyperactivity-impulsiveness, and three subcategories, predominantly inattentive, predominantly hyperactive-impulsive, and combined types.5,6
ADHD can cause academic, social, and psychological problems, adversely affecting a child’s self-esteem and ability to reach his or her full potential. Studies have shown that without treatment, children with ADHD are at an increased risk of lower academic achievement, injuries, alcohol or substance abuse, and early pregnancy.6
The precise etiology of LDDs is unknown, but many factors (eg, genetics, environmental toxins, nutrition) are implicated. More research continues to focus on the impact of environmental neurotoxins on brain development and function, including attention, learning, and behavior. Neurotoxins can damage, destroy, or impair nerve tissue; interfere with brain development; and disrupt the endocrine (hormone) system.1,4,6
Pesticide Use on the Rise
In the past 50 years, the use of agricultural pesticides has increased significantly as large-scale commercial farms have replaced family-operated farms. Pesticides are neurotoxins developed to kill pests (eg, rodents, insects, weeds, fungi) that hinder crop growth. The generous use of pesticides, synthetic fertilizers, hormones, and antibiotics has become routine to ensure optimal crop yield.
In 1939, the organochlorine called dichlorodiphenyltrichloroethane (DDT) was discovered as an inexpensive and effective pesticide. DDT was widely used until the early 1970s when harmful environmental effects couldn’t be ignored. In 2004, more than 100 countries signed the Stockholm Convention on Persistent Organic Pollutants, banning the use of DDT and other pesticides. However, DDT is still used to kill mosquitoes in several southern African and Asian countries where malaria is endemic. Experts reason that malaria is a greater threat to health and life than DDT exposure. More than 700,000 African children die yearly from malaria.7,8
Despite being banned 40 years ago, DDT and its residues remain in our environment and the adipose tissue of a large population of humans today. DDT and its metabolite dichlorodiphenyldichloroethylene (DDE) are classified as endocrine disruptors. Evidence suggests there’s an association between long-term DDT and DDE exposure and preterm birth and low birth weight; growth reduction in boys; earlier puberty in girls; adverse pregnancies; endocrine disorders, including diabetes; breast cancer in women; reduction in semen quality in men; and risk of cancer. The Environmental Protection Agency (EPA) considers DDT a probable carcinogen, while the U.S. National Toxicology Program states DDT is “reasonably anticipated” to be a human carcinogen.7,8 A 2007 study concluded that American women exposed to high levels of DDT before midadolescence had a five-fold increase in the risk of developing breast cancer.9
Still, the OP class of pesticides is the most common and heavily used in the United States, widely applied to crops of corn, soy, wheat, and various fruits and vegetables. As of 2010, the EPA had registered 32 OP pesticides. The EPA considers residue in food and drinking water, as well as residential pesticide use, important sources of exposure. The Centers for Disease Control and Prevention regards diet as the major source of pesticide exposure for infants and children.1,10
Children at Risk
A fundamental principle in pediatric medicine and nutrition is that “children are not little adults.” This observation is especially relevant regarding children and neurotoxin exposure. The EPA and the National Academy of Sciences report that “standard chemicals are up to ten times more toxic to children than to adults, depending on body weight.”1-3
At conception, children are more vulnerable to harm from toxic chemical exposure than adults. Immediately after conception, cells begin rapidly dividing as the brain and organ systems develop. Even a tiny dose of a neurotoxic chemical early in the prenatal period can interfere with or impair healthy brain development. The fetus, depending on the stage of development, is selectively sensitive to particular neurotoxins.1-4 Two birth cohort studies suggest that increased levels of OP exposure in utero resulted in greater numbers of abnormal reflexes in newborns.1 A study of 329 California 7-year-olds, primarily children of Latino farm workers, found an association between prenatal exposure to OP pesticides and lower IQ scores.11
Exposure to OP pesticides may initially occur in utero, but as infants and children grow, their exposure is likely to increase through diet and outdoor activities. Infants take more breaths per minute and have more skin surface relative to their body weight than adults; therefore, their exposure to pesticides is greater than adults. Infants and young children engage in hand-to-mouth behaviors that can increase their risk of environmental exposure. Children live and play closer to the ground than adults, so their risk of exposure to volatile pesticide vapors is greater. In addition, children, more often than adults, eat and drink relative to their body weight, which can lead to higher exposures of pesticide residue per pound of body weight.1,2,11
Even chronic low-level neurotoxin exposure can be harmful because children’s immune systems are immature, and the activity and expression of detoxifying enzymes is reduced. The potential for harm exists into late adolescence as the brain continues to develop.1,2,4,10
Neurotoxic Properties and Effects
OP pesticides act by impairing acetylcholinesterase, the enzyme responsible for the degradation of acetylcholine, a neurotransmitter. Acetylcholine is essential to skeletal-muscle motor neurons, peripheral parasympathetic and sympathetic neurons, and multiple fibers in the central nervous system, including those that assist in regulating memory acquisition. Impairment of acetylcholinesterase causes an accumulation of acetylcholine, or choleric excess, in the central and peripheral nervous systems. This choleric excess results in continued stimulation followed by suppression of neurotransmission—it’s this effect that kills pests.1
There’s strong toxicological evidence demonstrating that repeated low-level exposure to OP pesticides adversely affects neurodevelopment and growth in developing animals. The findings from animal studies demonstrate a link between OP pesticide exposure in utero and impaired maze performance, locomotion, and balance postpartum.1,2
OP pesticides are harmful to humans as well. In the body, pesticides are broken down into compounds including dialkyl phosphate (DK) and dimethyl alkylphosphate (DMAP), which are detectable and measurable in urine. The harm caused in adults and children can vary depending on dose and length of exposure. Acute high-level OP pesticide exposure and poisoning is more likely to occur in an occupational or agricultural setting. The signs and symptoms of acute OP pesticide poisoning caused by cholinergic excess include copious respiratory and oral secretions, diarrhea, vomiting, sweating, altered mental status, autonomic instability, and generalized weakness.1,2
However, the signs and symptoms of chronic low-level OP exposure are subtler, and the lag time between exposure and manifestation of signs and symptoms varies (see below). With repeated exposure, even in small amounts, pesticides can build up in body tissue stores.1,2
Pesticides and Neurobehavioral Disorders
Emerging studies suggest a connection between OP pesticide exposure and the development of various neurobehavioral disorders, particularly ADHD. Kofman and colleagues found a link between an OP pesticide and delays in learning rates, reduced physical coordination, and behavioral problems, especially in children with ADHD.3 Two separate studies, both conducted in agricultural areas (one in Mexico and one in California’s Central Valley), have suggested a tie between increased levels of OP pesticides in children and a rise in maternally reported pervasive developmental disorder, an umbrella term for a group of disorders that includes autism and Asperger’s syndrome.12,13
Perhaps the most notable study to date was conducted by Bouchard and colleagues.4 This study, which caught the media’s attention and was widely reported, examined health data from 2000 to 2004 of 1,139 children aged 8 to 15 that was representative of the U.S. population. Children in this study who had higher urinary levels of the OP metabolites DK and DMAP were more likely to meet the diagnostic criteria for ADHD.4
While this study couldn’t and doesn’t prove that pesticides cause ADHD, it demonstrates a possible association between pesticide exposure and the risk of developing ADHD. Experts agree this research is persuasive, but more prospective studies are needed for clarification. This study was unique because it demonstrated that even in the smallest amounts, pesticides might affect neurotransmitters and brain and neurobehavioral development (eg, inattention, impulsivity, hyperactivity, learning difficulties).4
U.S. Pesticide Monitoring
The EPA is responsible for regulating pesticides under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) and the Food Quality Protection Act of 1996 (FQPA). In 1991, the Pesticide Data Program (PDP) was initiated for the purpose of pesticide data collection. The PDP plays an important role in administrating the FQPA, which mandates that pesticide residue data must be collected from the foods infants and children most frequently consume. The EPA uses PDP data to assess pesticide safety and tolerances (maximum residue limits). The EPA has maximum safety tolerance levels for some pesticides, and no tolerance safety levels for other pesticides. A no-tolerance level means there should be no detectable pesticide residues on produce. The EPA, the USDA, and the FDA are involved in the regulation, use, and safety of agricultural pesticides.7-9
Before pesticides are distributed, sold, or used, they must go through the EPA registration process, which can last as long as nine years and cost millions of dollars. A company seeking pesticide registration must provide data from various short-term and long-term tests performed according to EPA guidelines to evaluate the pesticide’s potential to cause harm. Criteria include cancer and reproductive system disorders in humans, wildlife, fish, and plants, including endangered species and nontarget organisms. In addition, possible contamination of surface or ground water from leaching, runoff, and spray drift is assessed.
A pesticide becomes registered when the EPA determines that the highest possible dose, either as a single exposure or chronic exposure, has a no-observable adverse effect level in experimental animals. The EPA then determines the reference dose (RD), the amount of a pesticide residue a person can consume daily for 70 years without any expected health-related problems. The RD is used as the toxicological indicator when pesticide residues are tested on foods designated for human consumption. A chemical classified as having no observable adverse effects differs from a chemical “proven safe” or secure from risk or harm.7-9
Most conventionally grown produce contains residues that are within the EPA allowable limits. Some produce may have residues from multiple pesticides. The U.S. Pesticide Residue Program Report (2008) found that 28% of frozen blueberries, 25% of strawberries, and 19% of celery samples had detectable concentrations of malathion, an OP pesticide, but residue amounts were within EPA safety levels.4 Malathion has been widely used since 1956 to eradicate mosquitoes, boll weevils, and fruit flies that threaten crop yields and transmit harmful viruses, pathogens, and diseases.7-9
Do pesticides pose a health risk at low levels of exposure that were once considered insignificant? A growing number of experts question the current acceptable “toxic threshold” level—the lowest exposure thought to be harmful.4
Biological monitoring in the United States indicates that pesticides and other contaminants are more prevalent than originally thought, with higher levels seen in some subpopulations. In a study of low-income pregnant women and newborns in New York City, detectable levels of OP pesticides were found in 70% of the women, and the cord-blood samples of 64% of newborns had detectable levels.1
Organic Foods Reduce Exposure
A 2003 study by Curl and colleagues reported that children aged 2 to 5 who ate conventionally grown foods had six times more urinary OP pesticide metabolites (DK and DMAP) than children who ate organic foods.14 Another study published in 2008 by Lu and colleagues involved 23 children aged 3 to 11 who consumed only conventional diets.10 During the one-year study, the children consumed conventionally grown foods but were switched to organic diets for five consecutive days in the summer and fall. Investigators obtained urine samples twice daily for seven, 12, or 15 consecutive days during each season of the year. They measured specific urinary metabolites of malathion, chlorpyrifos, and other OP pesticides. Concentrations of OP-specific metabolites were reported and classified into one of three categories: detectable, detectable but not quantifiable, or undetectable. Researchers found that children who switched from eating conventionally grown produce to eating organic produce had either undetectable or detectable but not quantifiable levels of urinary pesticide metabolites.14
Seven Frequently Asked Questions
The definition of organic has become clearer with the establishment of specific standards for growing and processing produce. But as you know, parents still ask dietitians for the definition of organic and guidance on purchasing these food items. Here are some of the questions parents often ask and answers you can provide:
1. How is organic produce different from conventionally grown produce? The philosophy of organic farming is the preservation of the cycle of life by utilizing food waste and manure to rebuild the soil for future food production. The primary goal of organic farming is to sustain ecological harmony and interdependence between soil, plants, animals, and humans.
The USDA defines organic as produce that’s grown without the use of most conventional pesticides, fertilizers made with synthetic ingredients or sewage sludge, bioengineering, or ionizing radiation. Organic crops must be grown on soil free of prohibited substances for three years before they’re classified as organic.
Organic farmers use renewable resources and value soil and water conservation. In contrast to long-lasting synthetic pesticides, botanical or nonsynthetic pesticides used in organic farming are quickly broken down by sunlight and oxygen. However, an estimated 10% to 25% of organic fruits and vegetables contain some residues of synthetic pesticides due to polluted groundwater and rain but in amounts significantly lower than conventional produce.
Organically produced whole foods will have a green and white organic seal on the label, indicating compliance to strict USDA organic standards and inspection. Packaged or commercially prepared foods that are labeled 100% organic have no synthetic ingredients, while foods containing a minimum of 95% organic ingredients are eligible to use the USDA organic seal. A packaged or commercially prepared food that’s labeled “made with organic ingredients” must contain at least 70% organic ingredients but cannot use the USDA seal.15
2. What’s different about organically produced meat, poultry, eggs, and dairy foods? Organic meat, poultry, eggs, and dairy foods come from animals that don’t receive antibiotics or growth hormones. The philosophy of organic livestock production is to provide conditions that meet the health needs and natural behavior of the animal. Organic livestock must be given access to the outdoors, fresh air, water, sunshine, grass, and pasture. Organic livestock must be fed 100% organic feed that’s free of any animal by-products, hormones, antibiotics, or other animal drugs. If an organic animal gets sick and receives antibiotics, it’s not considered organic any longer. Certified organic farmers must keep extensive records to trace the animal from birth to the market. Meat labeled organic is 100% organic—there’s no “partially organic” category.
3. Are organic foods safer? If safer means free from bacterial contamination and other harmful organisms, the answer is no. The USDA makes no claims that organic foods are safer to eat than conventional foods. The Organic Trade Association says organic products are as safe as conventionally produced foods. Because certified organic farmers adhere to strict guidelines for safe and hygienic food production and comply with all local, state, and federal health standards, one can infer that their products are grown and handled with care and may be less likely to become contaminated. However, any produce—organic and nonorganic—can become contaminated with harmful bacteria. To ensure food safety, one should follow proper hand- and produce-washing procedures as well as safe food storage and cooking practices.
4. Are organic foods more nutritious? There’s an ongoing debate about whether organic foods are superior to conventional foods in nutrient content. The USDA makes no claims that organic foods are more nutritious than conventional foods. A systematic evaluation of 162 studies, of which 55 were considered of satisfactory quality and extensively analyzed, found that conventionally produced crops had a significantly higher content of nitrogen, while organically produced crops had a significantly higher content of phosphorus and higher titratable acidity.16 The investigators concluded that the small differences detected in nutrient content were biologically plausible and most likely related to differences in production methods.16 However, it’s important to note that investigators of this systematic review didn’t consider the presence of contaminants (pesticides or other possible environmental toxins) as a factor in assessing nutritional value or safety.
Designing a scientific study to investigate and compare the nutrient content of organic and conventionally produced foods is a challenge, as it requires controlling for all variables (soil quality and condition and maturity at harvest) that could influence nutrient content. Despite the challenges of research design, a small number of studies indicate that organic produce has a greater mineral content than conventional produce.17 This higher mineral content is most likely due to the use of organic fertilizers (compost or manure). Diversity in local soil conditions is an important variable in nutrient content.
However, organic products may offer health benefits beyond mineral content. Some organic fruits and vegetables may have higher levels of phytochemicals compared with those conventionally grown. The use of organic fertilizers in organic farming results in plants with lower levels of nitrogen and nitrate. Dietary nitrate can be metabolized to nitrite and then converted in the presence of stomach acid to nitrosamines, which are linked to cancer development in animals and potentially humans. Much more research is needed in this area.15
5. Do organic foods taste better? There’s no clear scientific evidence to prove that organic produce tastes better; however, consumers of organics are adamant that the flavor and freshness of organic foods, especially locally grown produce, is superior to conventional foods. Taste is subjective and personal, and the power of suggestion may be at work here.
6. Is natural the same as organic? No. The terms “free range,” “hormone free,” or “natural” aren’t synonymous with organic. The term “natural” broadly refers to minimally processed foods that are free of synthetic preservatives, artificial additives, hydrogenated oils, stabilizers, and emulsifiers. Natural food products aren’t regulated; however, the USDA allows meat and poultry to use this term for products that have been minimally processed, that don’t differ fundamentally from the raw product, and that contain no artificial ingredients, such as carrageenan or monosodium glutamate. The majority of raw meat and poultry found in grocery stores fits this definition. Natural doesn’t mean hormone or antibiotic free.15
7. Are organics worth the price? That’s an individual decision. While most parents probably would prefer to purchase organic foods, the higher cost of organics is an obstacle. Organic foods cost an average of 50% more than conventionally grown produce. Nonetheless, organic food sales are increasing and are no longer just available in health food stores. Advocates of localism (the preference for food produced close to its market, usually on small farms) say reduced transport and storage costs can make these foods more reasonably priced.
Buying Organics on a Shoestring
Here’s what you can suggest to clients who wish to buy organic produce but are concerned about the cost:
• Make a grocery list based on planned menus. Suggest clients make a shopping list and stick to it. That way they’ll resist impulse purchases and allocate more grocery dollars for organic foods. Advise them to shop the perimeter of the store, since the most expensive processed foods are located in the interior aisles.
• Shop for seasonal produce. Seasonal produce is less expensive. Buy in bulk and freeze or can certain items to use later.
• Buy from local farmers’ markets and/or join a community co-op. It isn’t necessary to become a strict locavore, but if clients do a little research, they can identify nearby organic growers who can and will sell in bulk. Farmers’ markets are great places to meet fellow organic shoppers. And for a small monthly or annual fee, they can join a community co-op to get reasonably priced organic and local produce.
• Join a community-supported agriculture program. Members pay a weekly fee and in return receive a set amount of seasonal organic produce at reasonable prices. Generally, there’s a designated weekly pick-up location.
• Purchase frozen organic foods. Frozen organics can be found in most supermarket freezer sections and are usually less expensive than fresh organics.
• Buy generic or store brand organics. Many chain stores are offering their own brands of certified organic canned or frozen foods.
• Clip coupons. Suggest clients visit www.organiccoupons.com, a website that provides money-saving coupons for organic products.
• Prioritize purchases. It’s possible to become fixated on purity at any price. However, not all conventionally grown produce is created equal. Some are less contaminated with pesticide residues than others. See the chart below for a list of fruits that contain the highest and lowest amounts of pesticides. Clients can purchase organic varieties of those foods that have the most pesticide residues and buy the conventionally grown produce that has the least.
• Wash produce thoroughly to remove any lingering dirt, pesticide residue, and bacteria. The USDA advises consumers to wash fruits and vegetables (including produce with inedible skin) under cold running water. Clients can scrub fruits and vegetables if the outer surface or skin is firm. Don’t use soap since the FDA hasn’t approved the use of soap products on foods; consumers can ingest soap or detergent residues the produce absorbs. In addition, clients should remove any damaged or bruised parts on fruits and vegetables because potentially harmful bacteria can thrive in these nooks and crannies. And they should remove and discard the outer leaves of leafy vegetables, then wash the remaining leaves.
• Trim visible fat and skin from meat and poultry. Pesticide residues can collect in fat.
• Plant an organic garden. If planting a full-size garden seems overwhelming for clients, they can start with container gardening. Container gardens will enable clients to grow plants exclusively in containers instead of in the ground. They’re ideal for people living in apartments or urban areas or for those unable to plant a traditional in-ground garden. Moreover, working in the garden is a valuable opportunity for parent-child bonding and nutrition education.
— Carol Ann Brannon, MS, RD, LD, specializes in nutrition and feeding therapy for children and adults with developmental and learning differences in her private practice in metro Atlanta.
New ADHD Diagnosis Guidelines for Kids
On October 16, the American Academy of Pediatrics (AAP), at their annual national meeting and conference in Boston, released expanded guidelines for the diagnosis and management of ADHD in preschool children aged 4 and older. The previous AAP guidelines, issued 10 years ago, were written for the diagnosis and treatment of ADHD in children aged 6 to 12. This updated report, “ADHD: Clinical Practice Guidelines for the Diagnosis, Evaluation, and Treatment of Attention-Deficit/Hyperactivity Disorder in Children and Adolescents,” was published in the November issue of Pediatrics.
Possible Health Effects of OP Exposure1,2
• Runny nose
• Chest tightness
• Shortness of breath
• Stomach cramps
• Muscle twitching
Dirty Dozen (highest in pesticide residue)
Not-So-Dirty Dozen (lowest in pesticide residue)
Fruits: peaches, apples, nectarines (imported), strawberries, blueberries (domestic), grapes (imported)
Vegetables: sweet bell peppers, celery, spinach, lettuce, potatoes, kale/collard greens
Fruits: watermelon, grapefruit, kiwifruit, mangoes, pineapple
— Source: Environmental Working Group (www.ewg.org/foodnews/summary)
After completing this continuing education activity, nutrition professionals should be better able to:
1. Evaluate several reasons children are at greater risk of harm from pesticide exposure than adults.
2. Distinguish the signs of ADHD.
3. Examine the association between pesticide exposure and neurobehavioral conditions in children.
4. Illustrate the process for evaluating and regulating the safety of chemicals in the United States.
5. Provide dietary and budgetary guidance to consumers regarding the purchase of organic produce and foods.
1. The use of pesticides in the United States has:
a. increased in the past 50 years.
b. decreased in the past 10 years.
c. remained the same for the past 50 years.
d. improved crop yield without any proven harm to humans.
e. None of the above
2. The most common class of pesticides used today is:
b. organophosphates (OPs).
c. manure-based pesticides.
d. the new generation of DDT pesticides.
e. organic pesticides.
3. Research has shown that children with ADHD:
a. excel in the classroom and have a positive self-image.
b. are less likely to have injuries compared with children without ADHD.
c. have exceptional social skills.
d. if untreated, are at higher risk of drug and alcohol abuse and early pregnancy.
e. None of the above
4. At least one study found that exposure to OP pesticides in utero:
a. may be associated with lower IQ scores in children.
b. has little to no long-term effects on brain development.
c. is more likely to result in hyperactivity in boys than in girls.
d. has no effect on the reflexes of newborns.
e. All of the above
5. Which of the following statements is correct concerning pesticides?
a. Once the FDA approves pesticides, the USDA regulates them.
b. Pesticides must undergo strict testing outlined by the FDA and be proven safe before being used.
c. The Environmental Protection Agency (EPA) registers them once they’re found to pose no “reasonable certainty of harm.”
d. The USDA regulates and approves pesticides, and the EPA monitors them.
e. Pesticides are only toxic in large doses.
6. Which of the following is true about OP pesticides?
a. They’re only neurotoxic during the first trimester of pregnancy.
b. OP pesticides are water soluble and easily removed from produce with water.
c. They impair the activity of the enzyme acetylcholinesterase.
d. They’re not metabolized or broken down in the human body.
e. OP pesticides are primarily used for corn crops.
7. Emerging studies and research:
a. suggest an association between chronic low-level OP pesticide exposure and risk of developing ADHD.
b. found no association between chronic low-level OP pesticide exposure and risk of developing pervasive developmental disorder.
c. are focused on ethnicity and gender as a determinant in ADHD risk.
d. examined OP pesticide exposure risk exclusively in urban children.
e. are overwhelmingly funded by the petrochemical industry.
8. Which statement is correct concerning children and pesticide exposure?
a. Children are more vulnerable than adults to neurotoxins until age 2.
b. Adults are more at risk from pesticide exposure than children because adults eat more food.
c. Children are more vulnerable to pesticides because they engage in hand-to-mouth behaviors.
d. Children have mature and efficient detoxifying enzymes that act to prevent pesticide exposure impairment.
e. None of the above
9. Which of the following foods usually harbor the most pesticides?
a. Strawberries, carrots, and cabbage
b. Almonds, bananas, and kiwi
c. Wheat, rice, and barley
d. Bananas, pineapple, and broccoli
e. Avocados, mangos, and onions
10. Pesticide residues on conventionally produced foods:
a. are regarded as safe by the FDA.
b. may pose a health concern or risk for young children.
c. are considered neurotoxins.
d. are more prevalent than once thought.
e. All of the above
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15. Paul MW, Kemp G, Segal R. Organic foods: Understanding organic food labels, benefits, and claims. HelpGuide.org. Available at: http://helpguide.org/life/organic_foods_pesticides_gmo.htm. Accessed November 2011.
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17. Reganold JP, Andrews PK, Reeve JR, et al. Fruit and soil quality of organic and conventional strawberry agroecosystems. PLoS One. 2010;5(9):e12346.