Risk-Based Analysis of Environmental Monitoring Data: Application to Heavy Metals in North Carolina Surface Waters |
| |
Authors: | BENJAMIN L PRESTON JEREMIAH SHACKELFORD |
| |
Institution: | (1) Pew Center on Global Climate Change, 2101 Wilson Boulevard, Suite 550, Arlington, Virginia 22201, USA, US;(2) Carolina Environmental Program, University of North Carolina–Chapel Hill, Chapel Hill, North Carolina 27599-1105, USA, US |
| |
Abstract: | The state of North Carolina's Department of Environment and Natural Resources (NCDENR) conducts routine water quality monitoring
throughout the state to assess the health of aquatic systems. The current study reports the results of a retrospective (1990–2000)
ecological risk assessment of six heavy metals (arsenic, cadmium, copper, lead, mercury, and zinc) in 17 North Carolina basins
that was conducted to estimate the risk of heavy metal toxicity to freshwater organisms and assess the sufficiency of NCDENR's
monitoring data to identify water-quality-related ecological threats. Acute and chronic ecotoxicological thresholds (ETs)
were calculated for each metal based upon the 10th percentile of species sensitivity distributions and were normalized for
water hardness. Statewide probabilities (expressed as percentages) of a random sample exceeding acute or chronic ETs among
the six metals ranged from 0.01% to 12.19% and 0.76% to 21.21%, respectively, with copper having the highest and arsenic and
mercury the lowest risk. Basin-specific probabilities varied significantly depending upon water hardness and presumably watershed
development. Although the majority of specific sites where data were collected were at low risk for metal toxicity, some specific
sites had a high probability of toxic events associated with one or more metals. Analytical detection limits for metals were
frequently higher than estimated chronic ET, limiting the ability to assess the risk of chronic toxicity in soft-water basins.
Results suggest risk-based criteria may be useful for assessing and validating the sufficiency of monitoring programs and
prioritizing management goals. |
| |
Keywords: | : Ecological risk assessment North Carolina Heavy metals Geographic information systems |
本文献已被 PubMed SpringerLink 等数据库收录! |
|