Pesticides in the Environment: Monitoring in the Environment

Pesticides in the environment can be measured using many different techniques depending upon what medium is being tested and what the point of interest is. Sample collection for pesticide monitoring may range from grab samples out of waterways to the capture of fish or birds to test tissue levels. Most commonly, an area of concern will be monitored on a regular basis. It is possible to monitor soil, water, and air for amounts of pesticide.

Monitoring Soils

Soil properties play a large role in how pesticides are distributed through out the landscape. Soils that are subject to wind erosion can be a concern for airborne pesticides. Soils that allow water to flow through them quickly like sandy soils may be a concern for pesticide leaching which means that the pesticide will move through the soil with water or to a lesser extent through gas exchange. Unless there is reason to believe that unusually high amounts of pesticide exist, such as a chemical spill, soil is not generally monitored on a regular basis.

Monitoring Water

Humans are more interested in the water that leaves the soil, so more often wells, shallow water tables, aquifers, streams, and lakes will be monitored regularly to determine if pesticides or their degradation products are present. The Environmental Protection Agency (EPA) began recommending regular water monitoring for pesticides in the late 1970’s and early 1980’s when it was discovered that pesticides and/or their degradation products were showing up in groundwater and surface water studies. Since then, monitoring of water for pesticides occurs regularly in many areas.

Monitoring Air

Air is also of concern. Studies done in the recent past have found that air contains levels of pesticides that have been used in the past as well as those that are used today. However, several other environmental contaminant and quality issues take priority over pesticides in ambient air (meaning when there is not direct cause to suspect elevated levels of pesticides), and it is not common for air to be monitored regularly for pesticides. Also, rain causes the wet deposition of pesticides so often rain water will be monitored in favor of regular air monitoring because rain can be an indicator of amounts of pesticide in the atmosphere as well as pesticides that are being deposited on land or water bodies.

Monitoring Organisms

Tissues of organisms that humans eat such as fish are studied often to determine amounts of contaminants that are present so that recommendations can be made as to relatively safe levels of consumption. Pesticides are included in these studies if they have a tendency to bioaccumulate.

Resources

Coupe, R.H., M.A. Manning, W.T. Foreman, D.A. Goolsby, and M.S. Majewski. 1995. Occurrence of Pesticides in Rain and Air in Urban and Agricultural Areas of Mississippi, April-September 1995
http://toxics.usgs.gov/pubs/wri99-4018/Volume2/sectionC/2410_Coupe/pdf/2410_Coupe.pdf

Minnesota Department of Agriculture (MDA). Pesticide Monitoring in Water Resources 2003: Water Quality Monitoring Program.
http://www.mda.state.mn.us/

Minnesota Pollution Control Agency (MPCA). Minnesota 2001-2005 Non-point Source Management Program Plan (NSMPP).
http://www.pca.state.mn.us/water/nonpoint/mplan.html

Natural Resource Conservation Service (NRCS). 2000. Environmental Indicators of Pesticide Leaching and Runoff from Farm Fields.
http://www.nrcs.usda.gov/technical/land/pubs/eip_pap.html