What is Biomonitoring?

Biomonitoring is a field of scientific research which analyzes the tissues of humans or animals to detect and measure the subject's exposure to both natural and synthetic, or man-made, chemicals. Both natural and synthetic chemicals leave their impact on the body in one way or another through "markers." These markers can either be the actual chemical which remains in the body's tissues, or the by-products of its breakdown.

Biomonitoring measures what remains in the body's tissues after exposure to these chemicals. Biomonitoring does not, however, determine how the person or animal came in contact with the chemical, how they ingested it into the body, how long ago the exposure occurred, or whether the chemical exposure is actually harmful to the body. We know that natural and synthetic, harmless and toxic chemicals make their way into our soil, air and drinking water — what biomonitoring does is determine how much of it is making it into our bodies.

A biomonitoring study is generally conducted using the three following steps:

The tissues that most people think scientists would collect for a biomonitoring study are blood, urine and breast milk, but scientists also use hair, nails, fat, bone and even expelled air to conduct a biomonitoring study. Most chemicals are found in the body's tissues in extremely small quantities. Scientists measure the "body burden," or level of chemicals found in the tissues, in parts per million (ppm), parts per billion (ppb) and parts per trillion (ppt).

Certain circumstances affect "bioaccumulation" or "biomagnification," instances in which chemicals are found at much increased levels. This can occur when small animals which have been exposed to chemicals are consumed by a larger animal, and the chemical exposure is increased up the food chain. Environmental conditions such as weather can also affect the levels of certain natural chemicals released into the environment. Although biomonitoring does not provide conclusive information about how chemicals are ingested, or if they positively or adversely affect the body, it is an important component in the study of how our environment affects us physically.

Biomonitoring is the scientific technique of using living organisms to assess the quality of the environment, typically to monitor the presence of pollutants. By analyzing the tissues or behaviors of these organisms, scientists can infer the levels of contamination in an ecosystem. This method is crucial for detecting environmental changes and managing ecosystem health.

Biomonitoring is vital because it provides a direct measure of environmental pollutants in organisms, which can be more accurate than measuring the pollutants in air, water, or soil alone. It helps in understanding the cumulative impact of various pollutants on living organisms, including potential risks to human health, as indicated by the Centers for Disease Control and Prevention's National Biomonitoring Program.

Commonly used organisms in biomonitoring include benthic macroinvertebrates, fish, birds, and lichens. These species are chosen for their sensitivity to pollutants, their position in the food chain, and their ability to accumulate contaminants over time. For example, mussels and other filter feeders are often monitored for water quality due to their ability to concentrate toxins from the environment.

Traditional environmental monitoring methods involve measuring chemical, physical, and biological parameters directly from air, water, or soil. Biomonitoring, on the other hand, uses living organisms as 'bioindicators' to provide a more integrated assessment of environmental health. This approach can reveal the effects of pollutant mixtures and long-term exposure, which traditional methods might not detect.

Yes, biomonitoring can be used to assess human exposure to pollutants. By analyzing substances in blood, urine, or other tissues, scientists can determine the types and amounts of chemicals that individuals have been exposed to. The CDC conducts extensive human biomonitoring to track exposure to chemicals and assess public health risks.

Challenges in biomonitoring include the difficulty in identifying suitable bioindicator species, interpreting the results in the context of complex environmental interactions, and the ethical considerations of using animals for monitoring purposes. Additionally, the variability in individual organism responses to pollutants can complicate data analysis and the extrapolation of results to broader ecological or human health conclusions.