Health risk assessment for indigenous people of Сhukotka Autonomous Okrug exposed to persistent pollutants

The studies conducted in 2001 and 2010 included permanent residents of indigenous nationalities dwelling in the villages of Uelen and Kanchalan of Chukotka Autonomous Okrug. We assessed health risks from exposures to polychlorinated biphenyls (PCBs), DDT insecticides, lead, and mercury according to Guidelines R 2.1.10.1920–04 and U.S. EPA methods; a health survey was also conducted based on questionnaires. Health risks posed by ingestion of PCBs were mainly related to consumption of traditional foodstuffs contributing 84 % to the risk profile. Secondary contamination of food products from indoor surfaces accounted for 56 % of DDT-related health risks. For people of traditional occupations (hunters, fishermen, and reindeer herders) the risks of adverse health effects of PCBs were 5 times higher than for those of other occupations. Low income of the local population, high consumption of sea animal fat, alcohol abuse and ignorance of preventive measures resulted in 5–14 times increase in health risks posed by PCB exposures. Low socioeconomic status may significantly modify the health risks caused by bioaccumulation of persistent contaminants and heavy metals, its maximum impact being observed in the coastal areas of Chukotka and mainly in relation to PCBs. For the residents of Uelen, the predicted carcinogenic risk (up to 1.0 × 10–3) should be considered unacceptable.

Leaching of lead from clinoptilolite at acidic conditions

The leachability of Pb2+ from natural greek clinoptilolite was investigated according to the standard procedures TCLP/EPA/RCRA (1311), EPA Methods 1310, 1320 and DIN 38414-S4. Through SEM/EDAX analysis it was shown that lead was uniformly loaded onto the particles subjected to acid treatment. Sorption was fast during the first few hours and equilibrium was practically attained after 24 h. pH was the dominant factor affecting leaching and for values 3 and higher less than 1% of the metal was leached out while at pH=1 up to 20% of the lead initially present on the solid was leached out. At 1.5 and 2, lead was re-adsorbed after initial leaching. % leaching after 24h was found to increase with increasing initial load (17 to 44% for 15 to100 mgPb2+/gclin). Agitation rate (50-180 rpm) and particle size (1.4-2 mm and 5-6 mm) did not affect leaching. Higher temperature (25-40 oC) resulted in increased leaching rates. Despite the limited number of data, leaching seems to follow third-order kinetics. Finally, exposure to acid conditions increased markedly the specific surface (from 35.1 to 79.4 m2 g-1) and lowered the average pore diameter (from 80.8 to 42.9 Å) of the clinoptilolite particles.

Critical applications of SW 846 US EPA methods to evaluation of marine samples quality

Technical evaluation of analytical data is of extreme relevance considering it can be used for comparisons with environmental quality standards and decision-making as related to the management of disposal of dredged sediments and the evaluation of salt and brackish water quality in accordance with CONAMA 357/05 Resolution. It is, therefore, essential that the project manager discusses the environmental agency's technical requirements with the laboratory contracted for the follow-up of the analysis underway and even with a view to possible re-analysis when anomalous data are identified. The main technical requirements are: (1) method quantitation limits (QLs) should fall below environmental standards; (2) analyses should be carried out in laboratories whose analytical scope is accredited by the National Institute of Metrology (INMETRO) or qualified or accepted by a licensing agency; (3) chain of custody should be provided in order to ensure sample traceability; (4) control charts should be provided to prove method performance; (5) certified reference material analysis or, if that is not available, matrix spike analysis, should be undertaken and (6) chromatograms should be included in the analytical report. Within this context and with a view to helping environmental managers in analytical report evaluation, this work has as objectives the discussion of the limitations of the application of SW 846 US EPA methods to marine samples, the consequences of having data based on method detection limits (MDL) and not sample quantitation limits (SQL), and present possible modifications of the principal method applied by laboratories in order to comply with environmental quality standards.