Ecological, Groundwater, and Human Health Risk Assessment in a Mining Region of Nicaragua

Abstract

The objective of the present study was to integrate the relative risk from mercury exposure to stream biota, groundwater, and humans in the Río Artiguas (Sucio) river basin, Nicaragua, where local gold mining occurs. A hazard quotient was used as a common exchange rate in probabilistic estimations of exposure and effects by means of Monte Carlo simulations. The endpoint for stream organisms was the lethal no-observed-effect concentration (NOECs), for groundwater the WHO guideline and the inhibitory Hg concentrations in bacteria (IC), and for humans the tolerable daily intake (TDI) and the benchmark dose level with an uncertainty factor of 10 (BMDLs(0.1)). Macroinvertebrates and fish in the contaminated river are faced with a higher risk to suffer from exposure to Hg than humans eating contaminated fish and bacteria living in the groundwater. The river sediment is the most hazardous source for the macroinvertebrates, and macroinvertebrates make up the highest risk for fish. The distribution of body concentrations of Hg in fish in the mining areas of the basin may exceed the distribution of endpoint values with close to 100% probability. Similarly, the Hg concentration in cord blood of humans feeding on fish from the river was predicted to exceed the BMDLs(0.1) with about 10% probability. Most of the risk to the groundwater quality is confined to the vicinity of the gold refining plants and along the river, with a probability of about 20% to exceed the guideline value.

Temporal and spatial distribution of waterborne mercury in a gold miner's river

“…The probability by which the present WHO drinking water guidelines (2005) would be exceeded by human exposure to the TDHg concentrations in the Artiguas river is less than 10 À4 , even at the most contaminated site 2 (based on the probability density functions in ref. 37), and it is still less than 1% if the THg concentrations are considered. The TDHg concentrations may lead to a higher risk to aquatic bacteria and fish in the stream than to humans and exceed the hazard endpoints for both groups by a probability of about 1% at sites 2-5.…”

Non-Cancer Human Health Risk Assessment From Exposure to Heavy Metals in Surface and Groundwater in Igun Ijesha, Southwest Nigeria

“…The exposure heavy metals has been associated with a wide variety of adverse health effects, including cancer (Adeyemi et al, 2007;Ghanem and Ghannam, 2010). Other health impacts associated with ingestion of heavy metals such as Arsenic (As), leads (Pb), Manganese (Mn), Chromium (Cr), Cadmium (Cd), Zinc (Zn) Nickel (Ni) are many and well documented (Picado et al, 2010;Alamelumangai and DeviShree, 2012). In order to assess risks arising from ingestion of heavy metals of individual organisms, Rikken and Lijzen (2004); Hacon et al (2010) said that it is important to consider their food habits, behavioural patterns and habitat requirements because these factors have effects on the exposure of individual organisms to heavy metals and associated risk of exposure (Hacon et al, 2010;Ndimele et al, 2011).…”

NMR-based metabolic profiling for serum of mouse exposed to source water

“…Recently, several studies have been conducted to investigate metabonomic and other toxicity of drinking water sources (Picado et al 2010;Wang et al 2010;Wu et al 2009;Zhang et al 2009). However, different from other types of water, Taihu Lake source water contains PAHs, and the concentration of which exceeded the Drinking Water Standards of the USEPA (2009).…”