Count down to Expo!

     It is common knowledge that pesticides are bad bad for the environment. One of the side effects of pesticides commonly cited is the contamination of waterways. However, very few people know exactly what this means. Runoff from pesticides can contaminate waterways in several ways. The first way is through surface contamination. This is when pesticides mix with water on the surface of the earth and usually occurs after rain or another form of precipitation (FAO). This is also the most common and basic form of contamination in waterways. Another form of contamination is when pesticides enter the food web, often as a direct result of the aforementioned surface contamination (EPA). This is where most of the negative impacts come from. Due to the process of bioaccumulation, the higher up in the food chain an organism is, the more exposure to these toxins that it will face. Exposure to toxins can, and often do, result in a myriad of health issues, such as reproductive issues and deformations.

    The impacts of pesticides in aquatic systems is affected by several factors. The main factors that affect these systems are the toxicity and persistence of the pesticides as well as what degradates it makes (FAO). How toxic a pesticide is determined by what concentration of the toxin proves fatal to an organism. The lower the LD (lethal dose) is, the more toxic it is and the more harmful it is to the environment. The second aspect that affects the impacts of a pesticide is the persistence of it, or its half life. A pesticides half life is how long it takes for its ambient concentration to decrease by 50%, known as the degradation of a pesticide (FAO) Though most of today’s pesticides have short half-lifes, they can still wreck havoc on an aquatic system (Perlman, Howard). The third aspect that affects the impacts of a pesticide on an aquatic system is the degradates that it produces. Degradates are the additional chemicals formed by the degradational processes. These degradates can have lesser, equal or even greater toxicity than the parent pesticide.(FAO).