Journal of environmental & analytical toxicology最新文献

In 2006, the Agency for Toxic Substances and Disease Registry received a request to determine whether a cluster of polycythemia vera patients existed in a northeast Pennsylvania community. A significant cluster of PV cases was identified at the nexus of three counties near several hazardous waste sites. The current study evaluated the potential for a select number of environmental contaminants previously detected in the cluster area to induce DNA damage using in vitro assays with hematopoietic stem-cell derived progenitor cells. CD34+ cells were isolated from normal cord blood samples and were cultured for 48-72 hours to generate erythroid progenitor cells. Eighteen compounds were chosen for the assay; arsenic trioxide, benzo(a)pyrene, benzene, methylene chloride, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), trichloroethylene, potassium chloride, ethylbenzene, benzo[k]fluoranthene, styrene, cadmium chloride, hydroquinone, 1,1,1-trichloroethane, sodium cyanide, manganese chloride, chromium oxide, lead oxide, and sodium arsenite. Genotoxicity of the compounds was determined using the comet assay, and toxicity determined via the cell viability assay. Using the comet assay, 16 compounds at 10 nM concentration, induced a significant amount of DNA damage compared to the control. When evaluating whether a dose-dependent relationship was present, seventeen of the eighteen compounds led to greater DNA damage with increasing exposure concentrations. 2,3,7,8-TCDD was particularly potent, inducing DNA damage in virtually all cells at 1 μM. In conclusion, most of the toxins evaluated using the comet assay showed potential to induce DNA damage in hematopoietic cells, and the genotoxic effects were dose-dependent.

Urbanization adjacent to rivers has increased in recent years and is considered a source of environmental contamination. The resulting increase in number of urban rivers in highly populated areas, such as the Caribbean island of Puerto Rico, has led to the appearance of synthetic as well as naturally occurring chemicals not previously observed nor regularly monitored in freshwater habitats. Some of these chemicals, such as heavy metals and plasticizers, have been shown to affect endocrine, respiratory, and nervous system function in animals and humans, even at relatively low concentrations. The purpose of this study was to measure concentrations of such emergent contaminants on rivers of urbanized areas on the northeast of Puerto Rico, as one element in the assessment of the impact of urbanism on water quality in these communities. To accomplish this, we used Inductively Coupled Plasma and Gas Chromatography Mass Spectrometry to measure amounts of heavy metals and phthalates, respectively, in superficial water of three rivers of Puerto Rico: Mameyes (non-urban), Río Piedras (urban river without a dam), and La Plata (urban river with a dam). The urban rivers had significantly higher concentrations of heavy metals arsenic, barium, cadmium, manganese, and antimony, when compared with the reference non-urban river. Manganese was the only metal found in concentrations higher than limits established by the EPA for drinking water. Of eight phthalates amenable to measurement with the chosen protocol and instrumentation, only dibutyl phthalate was detected, only in the La Plata river, and at concentrations ranging from 3 to 8 parts-per-billion. These findings suggest that urbanism close to rivers of Puerto Rico is likely having an impact on water quality and thus further study to identify the potential sources, as well as the inclusion of these emergent contaminants on the list of chemicals regularly monitored by government agencies is justified.