In 1891, when organic chemistry was only a nascent discipline, Russian chemist Alexander Dianin discovered bisphenol A (BPA). Though now a household name, the compound remained commercially anonymous until the 1930s, when British biochemist Edward Charles Dodds tried to use it as a synthetic estrogen to treat menopause, but found it too weak to be effective. BPA resurfaced in the 1950s as the key building block for epoxy resins and polycarbonate plastics. Since then, these materials have become ubiquitous as protective coatings on food cans, adhesives, and plastic components in electronics, automobiles, furniture, food equipment and containers.
BPA’s use in food products necessitated safety testing, but in the 1950s, toxicologists presumed that at the very small doses present in food containers, the chemical was essentially non-toxic and effects would be minimal. However, BPA challenged the “dose makes the poison” dogma when in 1997 researchers observed adverse chronic responses to low doses of the substance in laboratory mammals. Doses in the parts per billion range increased the size of prostrates in adult male mice who were exposed as fetuses.
These results are consistent with the activity of endocrine disruptors, a class of chemicals that, according to the National Institutes of Health “interfere with the body’s endocrine system and produce adverse developmental, reproductive, neurological, and immune effects in humans and wildlife.” BPA is one of many compounds in this category, which also includes other plasticizers, dioxins, pesticides, steroid hormones and some pharmaceuticals. While the worst of these compounds have been banned, and some are regulated, new chemicals used in materials are not required to undergo rigorous testing before they go into regular use. If these chemicals leach into the environment, they can have unforeseen, harmful effects. Endocrine disruptors are unique in that they can alter normal cell functioning in the parts per billion to parts per trillion ranges. To trace these chemicals, we must be able to identify and quantify them. But these very low concentrations are difficult to measure, especially in messy environmental samples.
Unlike laboratory samples, environmental samples are a complex mixture of known and unknown components—salts, minerals, microbes, natural organic material, and sometimes toxic pollutants. Oftentimes, scientists don’t even know what the pollutants might be. Known chemicals can react with light, organic material, minerals, or microbes to form new compounds, some of which can be even more harmful than the original contaminants. Advances in analytical technology and methods are finally making the identification and measurement of these compounds possible. Improvements in analytical laboratory equipment, instrument capabilities, and computing and data management have allowed scientists to more accurately detect compounds at lower concentrations and to analyze and compare results more efficiently and effectively than ever before. This enables us to do a better job monitoring our watersheds, agricultural soils, and drinking water to keep people and wildlife healthy.
While advanced analytical techniques have worldwide application for measuring contaminants, there are prime examples of their relevance here in Colorado. In 2006, U.S. Geological Survey scientists found antibiotics and antimicrobial agents downstream from a wastewater treatment plant and even in pristine reaches in the Boulder Creek watershed. Endocrine disrupting compounds were detected in the parts per billion range, and fish populations in waters downstream of a wastewater treatment plant exhibited symptoms of endocrine disruption like low male-to-female sex ratios and hermaphroditic fish. These effects are not isolated to Colorado; researchers have discovered endocrine disruption in fish populations across the globe, and long-term exposure can result in severe consequences such as the collapse of fish populations.
New technologies can also introduce harmful chemicals into the environment. Hydraulic fracturing, a nationally burgeoning industry, employs and extracts numerous chemicals that can have endocrine disrupting effects. Surface and belowground spills, as well as wastewater that has been inadequately treated at local plants (due to a lack of regulations on many compounds produced in oil and gas operations), can contaminate local rivers, drinking water sources, and agricultural soils. With over one million gallons of water spilled, and nearly 8 billion gallons of water produced in hydraulic fracturing operations in Colorado this year, it is imperative that we are capable of detecting hazardous compounds like endocrine disruptors and using that information to implement appropriate regulatory standards and remediation technologies.
Our health and the health of our environment depend on our ability to detect hazardous compounds at biologically relevant concentrations. Environmental analytical chemists and toxicologists at the USGS, the EPA, and other agencies and universities continue to use and develop sensitive techniques to identify and measure these chemicals and their byproducts, whether they come from plastics, wastewater, or hydraulic fracturing fluids. Modern products and processes can taint life-sustaining water with drugs and other potentially harmful chemicals. It is important that the public continues to support efforts to investigate environmental contamination so we can create effective policies that promote clean, safe drinking water, rivers, and soils.