(Beyond Pesticides, July 8, 2010) Just over a year after the Ontario ban on cosmetic pesticides, an Ontario study found an over 80% decline of the most commonly used lawn pesticides in urban stream and creeks. Staff of the Ministry of Environment and Conservation Authorities conducted a water quality monitoring study of 10 urban streams and creeks in Ontario. The study was conducted pre/post cosmetic pesticide ban in Ontario, during the summer of 2008 and 2009.
The report looks at 168 stream water samples that were taken over 2008 and 2009, which compares the water quality before and after the ban took effect. Sampling points were selected in areas mainly influenced by residential run-off — away from golf courses, sewage treatment plant effluents, and agricultural applications. The samples were analyzed for 105 pesticides and pesticide degradation products.
Preliminary results show a significant drop in concentrations of three commonly used lawn care products: 86 % of 2,4-D, 82% of dicamba, and 78% of MCPP. Previous estimates indicate that these three herbicides accounted for over half the total amount of pesticides used by lawn care companies in Ontario.
On the other hand, concentrations of some pesticides did not significantly change. Other pesticides commonly detected in urban stream water include glyphosate and carbaryl. The results for glyphosate are attributed to its continued use in exempt applications: to kill weeds and vegetation in urban and agricultural settings. The study suggests that carbaryl is used to control pests on lawns and gardens and agricultural crops, and to control fleas on household pets. Some environmentalists speculate that it might be due to its persistence in sediment.
On Earth Day, April 22, 2009, Ontario, Canada banned the use of over 250 pesticide products for cosmetic (lawn care) purposes, with no exceptions for pest infestations (insects, fungi or weeds) in these areas, as lower risk pesticides, biopesticides and alternatives to pesticides exist. It does not affect pesticides used for farming or forestry, and golf courses are exempt, but must meet certain conditions to minimize environmental impacts. There are no exceptions for pest infestations (insects, fungi or weeds) for lawn care in these areas, as lower risk pesticides, biopesticides and alternatives to pesticides exist. However, pesticides are still allowed for control of mosquitoes and other insects determined to represent a health threat.
Studies by public health experts are showing growing evidence of the potential health risk of pesticides, particularly for children. For information on alternative solutions to chemically intensive lawncare, see Beyond Pesticides’ Lawns and Landscapes page.