Environmental Effects of Pesticides

In addition to the effects pesticides have on humans, they also indirectly affect us through the impact they have on the environment. They end up in the water supply through runoff, and they stay in the soil, affecting plants and the animals who feed on them.

Pesticides are often sprayed over large areas, which means they may end up landing on crops other than the ones they’re meant to target. They can damage crops and affect the food supply. They can also end up disrupting animals’ natural habitats, killing those animals, or causing birth defects. One pesticide, atrazine, can turn male frogs into females. A study showed that one in 10 male frogs end up as females when they’re exposed to this pesticide; 75% of the male frogs in the study were essentially chemically castrated. This pesticide had a similar effect on fish and rodents. This effect can skew an animal population so badly that it ends up being wiped out.

Pesticide use has dramatically decreased the bee population. We rely on bees to pollinate certain food crops, and when their numbers become lower, less of those crops are available for us to eat. More than a quarter of bees worldwide died at the end of 2006 and the beginning of 2007. That cost the US agricultural economy $8-12 billion. Crops affected include oranges, apples, cucumbers, cherries, grapes, watermelons, squash, and almonds.

Pesticides can increase asthma – but not only through their chemicals irritating the respiratory system. Research shows that pesticides can impact global warming: in turn, global warming affects how much ragweed grows. Ragweed is a plant whose pollen is a powerful allergen. It’s thought that ragweed is responsible for more allergy and asthma problems than all other allergenic plants combined. A two-year study of ragweed indicated that as temperatures grew warmer and more carbon dioxide was released into the atmosphere, ragweed grew more prolifically and its pollen production increased. This meant that more people suffered from allergy attacks and allergy-related asthma.