If a grower uses recommended practices and observes precautions on labels, the application of pesticides should not create environmental problems. The federal regulatory system requires that pest control products undergo rigorous testing in areas such as producer and consumer safety, product effectiveness, and environmental impact. Nevertheless, air may be subjected to pesticides in the form of spray droplets, mist, dust, or vapour. The potential for pollution from chemical pest control lies in the contamination of adjoining property and the environment due to spray and vapour drift. The lingering effects of pesticide and other chemical applications may also be potentially hazardous to non-target organisms, applicators, and people working under unusual weather conditions or where restricted entry intervals are not adhered to.
Primary nutrients are nitrogen, phosphorus, and potassium.
Secondary nutrients are sulphur, magnesium, and calcium, while micronutrients are iron, manganese, boron, chlorine, zinc, copper, and molybdenum. If applied in excess amounts, these nutrients can reduce crop yields and become toxic to plants, animals, and humans. Nutrient levels in the soil that do not damage plants may nonetheless be accumulated in plant tissue and become harmful to consumers of the crop. In addition, nutrients in excess of plant needs can leach and contaminate groundwater. Spills and improper storage of fertilizers may lead to toxic nutrient concentrations in soil if the facilities allow for leaching or runoff.