Autopsies confirmed that ingestion of a type of insecticide, known as an organophostate, killed 22 children and hospitalized dozens more in India on Wednesday, reported the AP. The tragedy occurred after the children ate a free school lunch.

In the United States, regulations set safe limits for agricultural chemical levels in foods. "Despite precautions and regulations, a few cases of children poisoned by pesticides have been reported in the United States," Chengsheng Lu of the Harvard School of Public Health told Discovery News. However, Lu noted that in the United States medical facilities stock effective antidotes to treat pesticide poisoning.

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Lu conducted a study in Washington state and Georgia that found organophosphate insecticide residues on 14 percent of children’s food samples and pyrethroid insecticides on 5 percent of samples. Although pesticide residues contaminated the food, they did not exceed the Environmental Protection Agency's safe limits. The journal Environmental Health Perspectives published Lu’s research.

Tests like Lu’s aren’t done on every apple and grape in the supermarket. High costs prevent widespread testing of foods in the United States, according to Arnold Schecter, of the University of Texas School of Public Health.

Schecter's research found chemicals, known as persistent organic pollutants and endocrine disruptors, in food sample from Dallas, Texas. The most common contaminants were DDT, endosulfans, aldrin, PCB and PFOA. Environmental Health Perspectives published Schecter’s research, as well.

“In large enough amounts and in genetically sensitive people, they can cause nervous system damage, reproductive and developmental system damage, immune system disruption, sometimes cancer, and in rare cases, at least in theory, death,” Schecter told Discovery News.

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The long-term effects of eating even “safe” levels of mixtures of pesticides and other chemicals may affect Americans' health, said Schecter.

Schecter offered tips to concerned parent on how to reduce exposure to pesticides and other contaminants.

“Some of these chemicals are fat-soluble and found in animal fats in dairy products such as ice cream, in fish, especially fatty fish such as salmon, and in meat containing higher amounts of fat than other meats,” said Schecter. “Ice cream, sherbet, yogurt or milk with lower fat content will have less dioxins and PCBs, as one example.”

Choosing leaner hamburger or cutting the fat off meat can help too, Schecter noted. Broiling also can reduce the quantity of toxic chemicals by causing fat to drip away.

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Besides foods, children can be exposed to pesticides in other ways.

“Lower social economic status population, such as families living in public housing, tends to have more opportunities to be exposed to pesticides, such as for pest control purposes,” Lu said.