Pesticides are commonly used chemicals that are used in many gardens to supposedly keep crops healthy and free of contamination from insects, animals, weeds, and fungus. However, pesticides also carry less obvious risks to the environment and to human health. The active ingredient in pesticides is intended to kill the intended target whether plant or animal. However, pesticides also pose the problem of poisoning and often killing plants and animals that are not intended targets. The risk of pesticides to other animals such as birds, bees, and household pets is great since just a minute exposure in small animals can be fatal.
Another risk of pesticides is that the intended targets often develop resistance to the chemicals over time, thereby making the pesticide ineffective. In these cases, greater quantities of pesticide are often applied to have any effect. The problem with this approach is that the non-target population humans, household animals, birds, bees, and other plant life are now exposed to even greater health hazards. The risks of all different types of pesticides are significant. Insecticidal soaps lead to additional stress for plants and causes plant death. Bacillus thuringiensis and neem are bacteria that can kill good insects. Horticultural oil is a special type of petroleum oil that can burn leaves as can potassium bicarbonate. Pyrethrins kill insects and bees. Finally, sabadilla also kills bees and is toxic to mammals.
The Environmental Protection Agency (EPA) is the government organization that regulates pesticide use. Although the EPA has approved many pesticides for general use, the human health hazards are also significant. When pesticides are applied to gardens, only a small fraction of the chemical reaches the target plant. The remainder is either tracked into homes, carried away in the wind, mixed with clouds and returned to earth in the form of rain (Hill 2002), or run off as groundwater into lakes and rivers thereby polluting drinking water (Flaborea 2004, Struger 2006). Pesticides can drift in the wind for up to 15 miles from the point of origin.
About 5% of Americans have been directly exposed to pesticides either by inhalation, drinking, or direct skin contact. Numerous studies have associated pesticide exposure with health problems such as cancer, diabetes, asthma, and reproductive and fetal disorders. These risks are exaggerated in children since they have a longer life expectancy, which allows more time for diseases to develop. Also, in proportion to body weight, children eat more fruit, vegetables, and juices all of which contain higher pesticide levels.
A recent clinical study sheds light on the enormous health hazards associated with these pesticides. This study enrolled over 57,000 people who applied imazethapyr a common crop pesticide for a living and reported the number who developed cancer over a 10-year period. People who applied this pesticide had a 137% greater chance for developing bladder cancer and a 78% greater chance for developing colon cancer compared to people with no exposure (Koutros 2009).
Non-Hodgkin lymphoma, leukemia and sarcoma all different types of cancer are caused by herbicides and the incidence of childhood cancer doubles when landscaping pesticides are used around the home (Daniels 2001). Pesticides also have worrisome effects on the reproductive system. The chemicals have been found in urine and semen of people exposed to the pesticide and there are more miscarriages and birth defects in people exposed to pesticides. Finally, pesticides are associated with Alzeimer's disease, Parkinson's disease, autism, and ADHD (Sanborn 2006).
Through the use of organic gardening without the use of dangerous pesticides there is no human or animal exposure to toxins, foods have greater nutritional value, fruits and vegetables have larger amounts of whole food vitamins and plant based nutrients called phytonutrients , and foods have better taste. This is not to mention that more exotic supplements as organic aloe vera juice are loaded with vital and natural nutrients above and beyond their conventional counterparts. Ultimately, organic gardening results in a cleaner environment and better health for animals and humans alike.
Dr. Linda Kennedy MS SLP ND
Daniels JL, Olshan AF, Teschke K, et al. Residential pesticide exposure and neuroblastoma. Epidemiology. 2001;12:20-7.
Flaborea D. Surface Water Pesticide Monitoring Program Summary Report. Ottawa: City of Ottawa; 2004.
Hill BD, Harker KN, Hasselback P, Inaba DJ, Byers SD, Moyer JR. Herbicides in Alberta rainfall as affected by location, use and season: 1999 to 2000. Water Qual Res J Can. 2002;37:515-42.
Koutros S, Lynch CF, Ma X, Lee WJ, Hoppin JA, Christensen CH, Andreotti G, Freeman LB, Rusiecki JA, Hou L, Sandler DP, Alavanja MC. Heterocyclic aromatic amine pesticide use and human cancer risk: results from the U.S. Agricultural Health Study. Int J Cancer. 2009 Mar 1;124(5):1206-12.
Sanborn M, Cole D, Kerr K, Vakil C, Sanin LH, Bassil K. Ontario College of Family Physicians. Pesticides Literature Review. (Version current at March 9, 2006).
Struger J, Fletcher T, Martos P, Ripley B, Gris G. Ontario Ministry of the Environment. Pesticide Concentrations in the Don and Humber River Watersheds (1998 - 2000). (Version current at March 9, 2006).