Pest Problem?

Before you reach for the pesticides, bug spray, or call an exterminator, consider that once you’ve sprayed, pesticide residue can remain years later. Luckily, there are resources to help inform you whether you want to use them in the first place and what to do after the fact to limit exposure and clean up pesticide residue.

There is little data on concentrations of pesticides found inside homes, but studies that do exist indicate that interior pesticide residues are the norm rather than the exception.

A U.S. EPA study conducted between 2005- 2006 found residue of the pesticide fipronil on floor wipes in approximately 40% of homes studied.

Another 2008 study measured pesticide residue within public housing dwellings in Boston, Massachusetts. Pesticides were detected in all of the homes including banned or restricted use products.

Pesticides will break down over time

The breakdown time is called the “half-life.” Half-lives can vary widely depending on environmental factors. The amount of chemical remaining after a half-life will always depend on the amount of the chemical originally applied. The process occurs more slowly indoors, leaving the possibility of residues for longer periods of time.  The pesticide DDT is an extreme example of a long half-life. DDT was banned from the U.S. in 1972, but it and its decomposition products are still found in soil samples today, over 45 years later.

All pesticides for sale in the U.S. must be registered with the U.S. Environmental Protection Agency (EPA). In the registration process, the EPA assesses potential human health and environmental risks by reviewing ingredients, data from studies, intended uses, and storage and disposal practices, among many other aspects.  If data arises at a later date regarding the safety of the product, the pesticide can have its registration withdrawn and that pesticide becomes illegal for sale in the U.S.

The EPA has a cooperative agreement with Oregon State University, which operates The National Pesticide Information Center (NPIC). The center provides objective, science-based information on a variety of pesticide related subjects, including pesticide products, recognition and management of pesticide poisonings, toxicology, and environmental chemistry. NPIC also lists state pesticide regulatory agencies, and provides links to their web sites.

Organizations dedicated to informing the public on pesticides

Beyond Pesticides (BP) provides the public with useful information on pesticides and alternatives to their use. With this information, people can protect themselves and the environment from potential adverse public health and environmental effects associated with the use and misuse of pesticides.

BP has created a database tool to access current and historical information on pesticide hazards and safe pest management.

For technical resources, the National Institute of Health, U.S. National Library of Medicine maintains databases on toxicology, hazardous chemicals, environmental health, and toxic releases. TOXNET is a toxicology data network with information on pesticides, among other chemicals.

The Pesticide Action Network (PAN) Pesticide Database is a one-stop location for toxicity and regulatory information about pesticides. The database and website are updated and enhanced by Pesticide Action Network North America (PANNA).

New Pesticide Regulations

In addition to persistent residues, exposure to airborne pesticides is a risk, especially in farming communities.  On Jan. 1, 2018 the California Department of Pesticide Regulation imposed regulations restricting farmers from spraying pesticides within a quarter mile (0.4 kilometres) of public K-12 schools and licensed daycare centers from 6 a.m. to 6 p.m. on school days. The regulations apply to crop dusters flying over fields, air blasters spraying orchards and fumigants along with most dust and powder pesticides that could be blown onto school grounds by the wind.

Complete information on the new regulations can be found here:

By Laurel Cain, Healthy Building Science, Environmental Inspector