Source Identification of Chemical Contaminants in Environmental Media of a Rural Settlement

Principal Component Analysis (PCA) was used to identify the source of contaminants in Ubeji settlement. The contaminants assessed are oil and grease, TPH and related heavy metals (Cd, Cr, Cu, Ni, Pb and Zn). A total of 48 groundwater, 100 surface water, 160 soil and 100 sediment samples were collected from the study site from March to August, 2011. Measurements of oil and grease and TPH in samples were done gravimetrically, while atomic absorption spectrophotometry was used for determination of heavy metals. The results show significant contamination, as TPH levels in groundwater and surface water range from 22 to 96 mg L-1, while soil and sediment levels range from 600 to 2300 mg kg-1. Also, Cd, Cr and Pb levels in the groundwater and surface water range from 0.02 to 0.47, 0.51 to 1.3 and 1.7 to 4.1 mg L-1, respectively while soil and sediment levels range from 0.04 to 0.48, 28 to 66, 45 to 69 mg kg-1, respectively. However, Cu, Ni and Zn are within safe limits. PCA revealed that the source of the contaminants is a refinery and petrochemical company located close to the settlement

Health Risk Assessment of Exposure to Metals in a Nigerian Water Supply

This article reports the health risk associated with chronic intake of metals in the municipal water supplies of Eleyele and neighboring towns in the Ibadan metropolitan area of Nigeria. A total of 42 composite samples, consisting of treated water from the water treatment facility and residential areas receiving personal-use water (i.e., tap water) directly from the facility, as well as raw water from the treatment facility's water supply dam were sampled twice every month for 7 months. Concentrations of the metals were determined by atomic absorption spectrophotometry. Among the metals studied, Cd, Co, Cr, and Pb were detected at concentrations higher than maximum regulatory limits. Cd, Co, Cr, and Pb concentrations in treated water at the treatment facility ranged from 0.08–0.10, 0.14–0.16, 0.04–0.22 and 0.07–0.36 mg L , respectively, while personal-use water ranged from 0.08–0.11, 0.15–0.29, 0.02–0.29, and 0.12–0.65 mg L , respectively. Likewise, concentrations of the metals at the dam ranged from 0.06–0.08, 0.17–0.20, 0.13–0.37, and 0.03–0.15 mg L , respectively. It is estimated that exposure to the metals in the water supply results in oncological and non-oncological systemic health risks higher than is generally acceptable for drinking water

Prioritizing hazardous pollutants in two Nigerian water supply schemes: a risk-based approach

Objective To rank pollutants in two Nigerian water supply schemes according to their effect on human health using a risk-based approach. Methods Hazardous pollutants in drinking-water in the study area were identified from a literature search and selected pollutants were monitored from April 2010 to December 2011 in catchments, treatment works and consumer taps. The disease burden due to each pollutant was estimated in disability-adjusted life years (DALYs) using data on the pollutant’s concentration, exposure to the pollutant, the severity of its health effects and the consumer population. Findings The pollutants identified were microbial organisms, cadmium, cobalt, chromium, copper, iron, manganese, nickel, lead and zinc. All were detected in the catchments but only cadmium, cobalt, chromium, manganese and lead exceeded World Health Organization (WHO) guideline values after water treatment. Post-treatment contamination was observed. The estimated disease burden was greatest for chromium in both schemes, followed in decreasing order by cadmium, lead, manganese and cobalt. The total disease burden of all pollutants in the two schemes was 46 000 and 9500 DALYs per year or 0.14 and 0.088 DALYs per person per year, respectively, much higher than the WHO reference level of 1 × 10−6 DALYs per person per year. For each metal, the disease burden exceeded the reference level and was comparable with that due to microbial contamination reported elsewhere in Africa. Conclusion The estimated disease burden of metal contamination of two Nigerian water supply systems was high. It could best be reduced by protection of water catchment and pretreatment by electrocoagulation

The health burden and economic costs averted by ambient PM 2.5 pollution reductions in Nagpur, India

National estimates of the health and economic burdens of exposure to ambient fine particulate matter (PM2.5) in India reveal substantial impacts. This information, often lacking at the local level, can justify and drive mitigation interventions. Here, we assess the health and economic gains resulting from attainment of WHO guidelines for PM2.5 concentrations – including interim target 2 (IT-2), interim target 3 (IT-3), and theWHO air quality guideline (AQG) – in Nagpur district to inform policy decision making for mitigation. We conducted a detailed assessment of concentrations of PM2.5 in 9 areas, covering urban, peri-urban and rural environments, from February 2013 to June 2014. We used a combination of hazard and survival analyses based on the life table method to calculate attributed annual number of premature deaths and disability-adjusted life years (DALYs) for five health outcomes linked to PM2.5 exposure: acute lower respiratory infection for children b5 years, ischemic heart disease, chronic obstructive pulmonary disease, stroke and lung cancer in adults !25 years. We used GBD 2013 data on deaths and DALYs for these diseases. We calculated averted deaths, DALYs and economic loss resulting from planned reductions in average PM2.5 concentration from current level to IT-2, IT-3 and AQG by the years 2023, 2033 and 2043, respectively. The economic cost for premature mortality was estimated as the product of attributed deaths and value of statistical life for India, while morbidity was assumed to be 10% of the mortality cost. The annual average PM2.5 concentration in Nagpur district is 34± 17 μg m−3 and results in 3.3 (95% confidence interval [CI]: 2.6, 4.2) thousand premature deaths and 91 (95% CI: 68, 116) thousand DALYs in 2013 with economic loss of USD 2.2 (95% CI: 1.7, 2.8) billion in that year. It is estimated that interventions that achieve IT-2, IT-3 and AQG by 2023, 2033 and 2043,would avert, respectively, 15, 30 and 36%, of the attributed health and economic loss in those years, translating into an impressively large health and economic gain. To achieve this, we recommend an exposure-integrated source reduction approach

Systemic chronic health risk assessment of residential exposure to Cd2+and Cr6+in groundwater

A health risk assessment was undertaken for residents of Ubeji community who consume groundwater contaminated with trace metals. A total of 96 composite groundwater samples were collected in the dry and wet seasons from 12 locally dug wells, which are major sources of groundwater to the community. Concentrations of the metals were determined by atomic absorption spectrophotometry and were found to vary with season. Among the metals studied, Cd , Cr , and Pb were detected at concentrations higher than maximum regulatory limits. Cd concentrations (mg L ) range from 0.03 to 0.06 and 0.02 to 0.05 in the dry and wet seasons, respectively, while Cr levels (mg L ) range from 0.59 to 0.67 and 0.34 to 0.53, respectively, for the two seasons. Also, Pb levels (mg L ) range from 2.8 to 3.4 and 2.7 to 3.1 in the dry and wet seasons, respectively. It is estimated that exposure to metals in the community drinking water results in carcinogenic and non-carcinogenic risks that are higher than the generally acceptable risks of drinking water. Therefore, the results indicate that the concentrations of the metals in the groundwater are high and the consumption of water from the community wells may result in systemic chronic health risk to the residents

Can the Indian national ambient air quality standard protect against the hazardous constituents of PM2.5?

Globally, exposure to ambient fine particulate matter (PM2.5) pollution claims ~9 million lives, yearly, and a quarter of this deaths occurs in India. Regulation of PM2.5 pollution in India is based on compliance with its National Ambient Air Quality Standard (NAAQS) of 40 μg/m3 , which is eight times the revised global air quality guideline (AQG) of 5 μg/m3.But, whether the NAAQS provides adequate protection against the hazardous components in PM2.5 is still not clear. Here, we examined the risk to health associated with exposure to PM2.5–bound polychlorinated biphenyls (PCB), heavy metals and polycyclic aromatic hydrocarbons (PAHs) in an Indian district averaging below the NAAQS. The annual average concentrations of PM2.5 mass, Σ28PCB and Σ13PAHs were 34 ± 17 μg/m3, 21 ± 12 ng/m3 and 458 ± 246 ng/m3, respectively. Concentrations of As, Cr, Mn and Ni in PM2.5 surpassed the screening levels for residential air. Substantial level of risks to health were associated with exposure to dioxin-like PCBs (Σ12dlPCB), PAHs, As, Cr and Ni. The hazard index or lifetime cancer risk were 240, or 9 cases per 1000 population, respectively. The estimated risks to health through exposure to hazardous components, except Ni, were greatest in rural areas, having a lower average PM2.5 con�centration, than urban or peri-urban areas, suggesting higher toxicity potential of rural combustion sources. The large disparity between the estimated risk values and the acceptable risk level suggests that it would take a more stringent standard, such as the global AQG, to protect vulnerable populations in India from hazardous compo�nents in PM2.

Prioritizing hazardous pollutants in two Nigerian water supply schemes: a risk-based approach

Objective To rank pollutants in two Nigerian water supply schemes according to their effect on human health using a risk-based approach. Methods Hazardous pollutants in drinking-water in the study area were identified from a literature search and selected pollutants were monitored from April 2010 to December 2011 in catchments, treatment works and consumer taps. The disease burden due to each pollutant was estimated in disability-adjusted life years (DALYs) using data on the pollutant's concentration, exposure to the pollutant, the severity of its health effects and the consumer population. Findings The pollutants identified were microbial organisms, cadmium, cobalt, chromium, copper, iron, manganese, nickel, lead and zinc. All were detected in the catchments but only cadmium, cobalt, chromium, manganese and lead exceeded World Health Organization (WHO) guideline values after water treatment. Post-treatment contamination was observed. The estimated disease burden was greatest for chromium in both schemes, followed in decreasing order by cadmium, lead, manganese and cobalt. The total disease burden of all pollutants in the two schemes was 46 000 and 9500 DALYs per year or 0.14 and 0.088 DALYs per person per year, respectively, much higher than the WHO reference level of 1 × 10−6 DALYs per person per year. For each metal, the disease burden exceeded the reference level and was comparable with that due to microbial contamination reported elsewhere in Africa. Conclusion The estimated disease burden of metal contamination of two Nigerian water supply systems was high. It could best be reduced by protection of water catchment and pretreatment by electrocoagulation

The burden of disease attributable to ambient PM2.5-bound PAHs exposure in Nagpur, India

Polycyclic aromatic hydrocarbons (PAHs) bound to PM2.5 are genotoxic carcinogens that can also elicit non-cancer effects. Previous studies report substantial burdens of PAHs-related lung cancer, but no estimate for other cancer types or non-carcinogenic burden. Here, we assessed the burden of disease, in DALYs/person/year, attributable to thirteen priority PAHs in PM2.5 in Nagpur district, for several endpoints linked to benzo[a]pyrene, to inform policy decision-making for mitigation. We conducted detailed assessment of concentrations of PAHs in nine areas, covering urban, peri-urban and rural environments, from February 2013 to June 2014. PAHs concentrations were converted to benzo[a]pyrene equivalent concentration for cancer and non-cancer effects using relative potency factors and relative toxicity factors derived from quantitative structure-activity relationships, respectively. We derived severity for each endpoint using GBD 2016 dataset. The annual average concentration of total PAHs in Nagpur district was 458±246 ng/m3, and results in 0.011 DALYs/person/year (49,000 DALYs/year), much higher than the WHO reference limit of 1×10-6 DALYs/person/year. PAHs-related burden follow this order: developmental (mostly cardiovascular) impairment (55.1%) > cancer (26.5%) or lung cancer (23.1%) > immunological impairment (18.0%) > reproductive abnormally (0.4%). The estimated DALYs/person/year is high. Mitigation intervention should target combustion sources having the highest level of exposure