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Inappropriate handlings of informal e-waste processing have increasingly become a global environmental and public health issue of concern. This study was conducted to quantify the concentrations of five heavy metals found in the environmental media at an exposed village and a reference village in Northern Vietnam. The correlations between a pair of the heavy metals found in a medium, and between a pair of the environmental media was found. The results showed that drinking water was safe for heavy metal exposure in both studied villages. However, at the exposed village, the levels of the heavy metals found in indoor soil were, in descending order, Pb (678.42 ± 846.11 mg kg -1 ) > Ni (148.77± 163.80 mg kg -1 ) > Cr (61.99 ± 42.50 mg kg -1 ) > As (7.62 ± 3.33 mg kg -1 ) > Cd (6.34 ± 12.39 mg kg -1 ). The levels of Pb, Cd, Cr, and Ni in indoor soil and surface dust in the exposed village were significantly higher than those in the reference village at p<0.001. The average concentrations of Pb, Cd, Cr, Ni and As in indoor soil were 3.57, 8.78, 1.90, 4.41, and 1.08 times, respectively, higher than those in outdoor soil at p<0.001. The levels of Pb and Cd found in indoor soil at the exposed village were 9.69 and 3.17 time, respectively, higher than the maximum allowable limits in Vietnam. Significant correlations between the pairs of the heavy metals in a medium and between the pair of the environmental media was found at the exposed village. This finding suggested that inappropriate activities conducted at an informal e-waste processing facility could be a major contributor to the heavy metal contaminations. This study highlighted the importance of release mitigation of a hazardous heavy metal from an informal e-waste processing facility to prevent its potential effects on human health.

PurposeThe consumption of rice that contains high levels of inorganic arsenic may cause human health risk. This study aims to determine As species concentrations, particularly iAs, in raw rice in Ho Chi Minh (HCM) City and its health risks.Design/methodology/approachA total of 60 polished raw composite samples of rice were purchased from traditional markets and supermarkets in HCM City. All samples were analyzed by HPLC-ICPMS for As species determination.FindingsMean concentrations of inorganic arsenic in all samples, which were purchased from supermarket and traditional market, were 88.8 µg/kg and 80.6 µg/kg, respectively. Overall, inorganic arsenic level was 84.7 µg/kg and contributed the highest proportion of arsenic species in rice with 67.7%. The proportion profiles for arsenic species were: As (III) (60 %); dimethylarsinic acid (32.2 %); As (V) (7.7 %) and methylarsonic acid (0.1 %). Inorganic arsenic level in raw rice was below the recommendation of World Health Organization. Using the benchmark dose recommended by the Joint FAO/WHO Expert Committee on Food Additives (JECFA), all exposure doses were lower than BMDL05. However, as the doses ranged from 3.0 to 8.6 of Margin of Exposure (MOE), the health risk of iAs from rice consumption remains public health concern.Originality/valueThe study results report on the surveillance data of the presence of inorganic arsenic in raw rice products, which are available in the supermarkets and traditional markets, and its health risk to consumers in a metropolitan city in Vietnam.

Noise exposure in the working environment is a major cause of hearing impairment for workers; an audiogram hearing threshold level above 20 dB is considered irregular. In this study, audiometric data were analyzed with the objective of assessing hearing loss among power plant workers based on their age, noise exposure level, years of working, and work characteristics. A cross-sectional study was conducted to assess hearing level data for 672 workers reserved by the Health Care Unit of the power plant. The most recent audiometric data presented during 2013-2015 were used in the statistical analysis at 5 % level of significance. It was found that the most dominant frequency with reference to age and work experience is the test frequency at 4,000 Hz. The most prominent suffering significant hearing loss for both ears is the age group of 50-60 years, consistent with more than 35 years of working. The most significant exposure level is noise level at 81-84 dBA for the left ear only. The work characteristics were found to be the most significant factor affecting hearing loss in both ears. The t-test reveals no significant difference in hearing loss in both ears at all test frequencies. Hearing loss is found to occur at 4,000 and 6,000 Hz; therefore, there is a necessity to implement noise control measures specifically for each work group. Although there is an educational and training program in the power plant, all workers should still be educated continuously on how to use hearing protection equipment correctly to enhance awareness of the hazards of noise to hearing. Periodic audiometry should be performed to early detect noise-induced hearing loss specifically the notch occurring at 4,000 and 6,000 Hz, together with engineering control in order to reduce unwanted sound.