Micropollutants in the Potomac Watershed

Background information

Nearly three-quarters of the tidal waters of the Chesapeake Bay are impacted by toxic chemicals known as micropollutants. Some of the most important groups of micropollutants include pesticides, pharmaceuticals, industrial chemicals, and petroleum combustion by-products. Micropollutants present an ecological risk to both humans and wildlife in the Chesapeake Bay watershed. Historically, polychlorinated biphenyls, or PCBs, have posed a particular legacy problem in the Washington, DC metropolitan region and in the Potomac River because PCBs can accumulate in fish tissue and limit the amount of regional fish that can be consumed. Chemicals like PCBs are currently under regulation and management through the Clean Water Act (CWA). Reducing the impacts of micropollutants through the CWA is improving the health and value of living resources in the Bay region.

Extraction tube
Using a centrifuge, tubes of samples are vigorously mixed in order to extract chemicals from of sediment, water, and fish.

An emerging group of micropollutants not under regulation by the CWA includes pharmaceuticals and personal care products (PPCPs), chemicals that are derived primarily from wastewater discharge. The environmental impacts of PPCPs along with pesticides are currently a major research thrust in PEREC at the Potomac Science Center at George Mason University. The goals of micropollutant research team in PEREC include:

  1. Developing new analytical methods to detect parts-per-trillion concentrations of PPCPs and pesticides in environmental matrices such as water, sediment, and biota using state of art analytical instrumentation, such as advanced liquid chromatography-mass spectrometry.
  2. Determining the presence and concentrations of PPCPs and pesticides in the tidal Potomac River ecosystem. An ongoing project is currently being conducted in Hunting Creek near the city of Alexandria, VA in collaboration with Alex Renew Enterprises.
  3. Assessing the ecological risk of PPCPs and pesticides in the tidal Potomac River in conjunction with PEREC researchers in ecology, fish biology, and geology.
  4. Providing new knowledge on the chemical fate and distribution of PPCPs and pesticides in the aquatic environment for the development of effective environmental management and policy.

The PEREC principle investigators in micropollutant research include Dr. Tom Huff (SRIF) and Gregory Foster (Department of Chemistry and Biochemistry), both of whom share a research lab at the Potomac Science Center (room 2303).

Study locations, current findings and future research plans

Students view the results of the GC-MS, which compares chemicals found in samples to known chemicals.

PPCP and pesticide research has several sampling locations and projects ongoing in the tidal Potomac River. The most intensive sampling is occurring in the vicinity of Hunting Creek (Alexandria, VA), but sampling is also carried out in Gunston Cove (Lorton, VA), the Anacostia River (Washington, DC) and Dogue Creek (Fairfax Co, VA). Current and developing student research projects focus on primary PPCP sources in the Potomac River, PPCP sediment geochemistry, bioaccumulation of PPCPs in the food web, and depositional histories of PPCPs in sediments through sediment coring and dating. A wide variety of PPCPs have been detected in water, sediments and biota in Hunting Creek (see Arya et al. below), and the research team is expanding the lists of PPCPs and pesticides measured to enhance the database and deepen our understanding of the presence, sources and impacts of micropollutants in the Potomac River.

Highlighted Publications

Arya, G., S. Tadayon, J. Sadighian, J. Jones, K. de Mutsert, T. Huff and G. Foster (2017) Pharmaceutical chemicals, steroids and xenoestrogens in water, sediments and fish from the tidal freshwater Potomac River (Virginia, USA). J. Environ. Sci. Health. A 52, 686-696.

Huff, T. and G.D. Foster (2011) Parts-per-trillion LC-MS(Q) analysis of herbicides and transformation products in water. J. Environ. Sci. Health. A46, 1-12.

Shala, L. and G.D. Foster (2010) Surface Water Concentrations And Loading Budgets of Pharmaceuticals And Other Domestic Use Chemicals in An Urban Watershed (Washington, DC, USA). Arch. Environ. Contam. Toxicol. 58, 551-561.

Thomas, P.M and G.D. Foster. (2005) Tracking acidic pharmaceuticals, caffeine and triclosan through the wastewater treatment process. Environ. Toxicol. Chem. 24, 25-30.

Thomas, P.M and G.D. Foster. (2004) Determination of nonsteroidal anti-inflammatory drugs, caffeine and triclosan in wastewater by gas chromatography/mass spectrometry. J. Environ. Sci. Health, Part A, 39, 1969-1978

Foster G.D., E.C. Roberts, Jr., B. Gruessner and D.J. Velinsky (2000) Hydrogeochemistry and transport of hydrophobic organic contaminants in an urban watershed of Chesapeake Bay (USA). Appl. Geochem. 15, 901-915.