Human health implications of trace metal contamination in topsoils and brinjal fruits harvested from a famous brinjal-producing area in Bangladesh.

A study was undertaken to determine the contents of trace metals in 60 topsoils and 80 brinjal fruits samples from a famous brinjal-producing area of Bangladesh using atomic absorption spectrophotometer. The study also looked at soil pollution levels, dietary intake of nutritionally important trace elements, and human health risks from toxic metals induced by dermal soil exposure and consumption of brinjal. The content of Pb, Ni, Cd, Cu, Fe, Mn, and Zn in brinjal fruits harvested from farmer's fields ranged from 0.204-0.729, 0.031-0.212, < 0.010-0.061, 1.819-2.668, 3.267-5.910, < 0.010-0.866 and 2.160-3.846 µg g-1, respectively, while the amount of Cr was negligible. The calculated enrichment factors showed that 70, 50, and 25% of soil sampling sites had values in the 2.00-5.00 range for Pb, Zn, and Cd, respectively, while 30% of sites had values > 5.00 for Cd, indicating moderate to significant enrichment of these metals in the soil. The study also revealed that brinjal consumption provides a tiny amount of nutritionally important trace elements required for an adult human. Regarding the computed incremental lifetime cancer risks (ILCR), the study revealed that the values for Pb and Ni in all samples and Cd in 40% of samples were several hundred times higher for males and females than the USEPA threshold level due to oral ingestion of brinjal fruits. In contrast, dermal exposures to soil trace elements were within an acceptable range. The PCA results revealed that the contents of Cd, Pb, Ni, and Cu in soils showed strong positive correlations with those elements present in brinjal. The current study suggests future traceability research, focusing on pinpointing potential entry routes for toxic elements into the vegetable food chain.

Human health exposure and risks of arsenic from contaminated soils and brinjal fruits collected from different producers and retailers levels.

A quantitative assessment was attempted to determine concentrations of total arsenic (As) in farmer's field soils and fruits of brinjal collected from two famous brinjals producing Upazila's, namely Melandaha and Islampur of Jamalpur district, Bangladesh. The study also evaluated cancer and non-cancer health risks for both males and females caused by dermal exposure of soils and dietary intake of brinjal grown in farmers' fields and sold at different markets of four country districts. The study findings revealed that 75% of soil sampling locations had enrichment factor (EFc) values > 1.5, indicating the anthropogenic sources of As, and 50% of the sites possessed EFc values within the range of 2.0-5.0 indicated moderate enrichment of As. The mean concentrations of As in brinjal grown in farmers' fields and retailers of different markets of four districts were 0.18 and 0.39 µg g-1, respectively. The soils of the study area exhibited negligible risk in terms of the calculated hazard quotient, hazard index and incremental lifetiame cancer risk (ILCR) values for As due to dermal and ingestion exposures. In contrast, the same values for As due to the dietary intake of brinjal were thousands of times greater than the threshold level in 40% of farmers' field and all retailers' levels samples. Compared to the producer/farmers' field samples, the calculated average non-carcinogenic and carcinogenic health risks were more than twice in samples collected from different retailers. The present study suggests further pinpoint investigation of potential entry routes of As in the supply chain through future traceability studies.

Sources, spatial variation, and speciation of heavy metals in sediments of the Tamagawa River in Central Japan.

Sediments of the Tamagawa River in central Japan were studied to explain the spatial variation, to identify the sources of heavy metals, and to evaluate the anthropogenic influence on these pollutants in the river. Sediment samples were collected from 20 sites along the river (five upstream, four midstream, and 11 downstream). Heavy metal concentrations, viz. chromium, nickel, copper, zinc, lead, cadmium, and molybdenum, in the samples were measured using inductively coupled plasma-mass spectroscopy. The chemical speciations of heavy metals in the sediments were identified by the widely used five-step Hall method. Lead isotopes were analyzed to identify what portion is contributed by anthropogenic sources. The total heavy metal concentrations were compared with global averages for continental crust (shale) and average values for Japanese river sediments. The mean heavy metal concentrations were higher in downstream sediments than in upstream and midstream samples, and the concentrations in the silt samples were higher than those in the sand samples. Speciation results demonstrate that, for chromium and nickel, the residual fractions were dominant. These findings imply that the influence of anthropogenic chromium and nickel contamination is negligible, while copper, zinc, and lead were mostly extracted in the non-residual fraction (metals in adsorbed/exchangeable/carbonate forms or bound to amorphous Fe oxyhydroxides, crystalline Fe oxides, or organic matter), indicating that these elements have high chemical mobility. The proportion of lead (Pb) isotopes in the downstream silt samples indicates that Pb accumulation is primarily derived from anthropogenic sources.