Environmental health laboratories test environmental matrices such as water, air, soil, surfaces and food to identify contaminants that could harm the environment or the public. Examples of these contaminants include PFAS, lead, radon and certain types of bacteria and viruses. These laboratories typically conduct two different types of testing: regulatory testing and non-regulatory testing as needed to address community environmental health questions.
Regulatory Environmental Testing
Environmental health laboratories are typically responsible for testing at least some contaminants that indicate if their jurisdiction is complying with federal regulations (such as the
Safe Drinking Water Act,
Clean Water Act,
Clean Air Act and
Resource Conservation and Recovery Act), or specific state or local regulations. When testing for federal regulations in particular, environmental health laboratories will likely need to use standard methods that use the same protocols to ensure test results are consistent between laboratories all across the US. In addition to these standard methods, environmental health laboratories employ quality management systems that ensure test results can be defended in the court of law.
Non-regulatory, Community Environmental Testing
Environmental health laboratories may also provide testing that help address important community health questions, such as: "What are the levels of a particular unregulated contaminant in my drinking water?", "Does my private well water meet Safe Drinking Water Act or other standards?" and "How is the recent accidental hazardous waste spill affecting the river I kayak in?" To be able to investigate these questions is an invaluable benefit to the communities they serve. Given sufficient resources, and in collaboration with other governmental environmental health agencies, these laboratories can invest their time in exploring issues that don't guarantee a monetary gain but may ultimately result in high public health costs if not addressed.
Surveillance of wastewater is an emerging strategy across the US and world to provide an early warning system of the presence of novel and low-frequency pathogens or contaminants within a community. If identified, these pathogens or contaminants can be isolated to the localized area that the sewage was collected from: a "sewershed."
Based on successes in Europe, the Middle East and parts of Asia, CDC, EPA and other researchers are examining how to sample all or parts of a sewershed and test those samples using qualitative PCR (qPCR) to determine the presence and absence of SARS-CoV-2, the virus that causes COVID-19. A positive sample can indicate the presence of infected individual(s) 5-7 days prior to them showing symptoms. Public health officials may be able to use that information to test all individuals in the sewershed to determine quarantine or other preventative measures. Wastewater surveillance cannot completely replace clinical testing, but it is additional early information that can help to circumvent unknown viral spreading.
Testing for Contaminants of Emerging Concern
Per-and polyfluoroalkyl substances (PFAS) are a group of man-made chemicals that have been produced around the globe since the 1940s. PFAS are resistant to heat, water and oil, making them a useful material in many products such as carpeting, waterproof clothing, upholstery, food packaging and fire-fighting foam.
Their resistant nature can also make them a human and environmental health risk. The US Environmental Protection Agency (EPA) has named PFAS emerging contaminants of concern due to their ability to persist in the environment for an extended period of time and bioaccumulate in animals and humans with prolonged exposure.
The historic use of PFAS has led to pervasive, low levels of the compounds in people, food and the environment throughout the United States and the world. While the impacts of PFAS on human health are not yet fully understood, exposures must be limited whenever possible. Learn more about PFAS and environmental health laboratories
Cyanotoxins are produced by a variety of Cyanobacteria genera, including Microcystis, Anabaena, Cylindrospermopsis and Planktothrix, among others, and are currently divided into three main classes based upon their effects on humans or animals, including pets, livestock and wildlife. Neurotoxins (e.g., anatoxins, saxitoxins) affect the nervous system, hepatotoxins (e.g., microcystins, cylindrospermopsin, nodularins) affect the liver and dermatoxins affect the skin. Other possible health effects from lifetime exposure to toxins such as cancer are being researched. The primary exposure route is ingestion of contaminated water, but skin contact and inhalation may also occur through recreational activities.
To assist environmental health laboratories as they face evolving cyanotoxin challenges in their jurisdictions, APHL's Environmental Laboratory Science Committee developed "A Freshwater Algal Toxin Guidance Document for Public Health Laboratories." They continue to monitor the state of the science on this issue.
Microplastics, or plastic fragments less than 5mm in length, pollute the environment from various different sources, including cosmetics, clothing and the industrial process. These plastics can absorb and release toxic chemicals into the surrounding environment. This can harm to the population as the chemical bioaccumulate in the environment and marine life.
APHL Environmental Laboratory Science Committee members and their laboratories are monitoring the state of microplastics science.
To learn more about environmental monitoring, email
Sarah Wright, manager, Environmental Laboratories.