Evaluation of the effect of an environmental management program on exposure to manganese in a mining zone in Mexico (original) (raw)
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Characterization of air manganese exposure estimates for residents in two Ohio towns
Journal of the Air & Waste Management Association, 2015
This study was conducted to derive receptor-specific outdoor exposure concentrations of total suspended particulate (TSP) and respirable (d ae ≤ 10 µm) air manganese (air-Mn) for East Liverpool and Marietta (Ohio) in the absence of facility emissions data, but where long-term air measurements were available. Our "site-surface area emissions method" used U.S. Environmental Protection Agency's (EPA) AERMOD (AMS/EPA Regulatory Model) dispersion model and air measurement data to estimate concentrations for residential receptor sites in the two communities. Modeled concentrations were used to create ratios between receptor points and calibrated using measured data from local air monitoring stations. Estimated outdoor air-Mn concentrations were derived for individual study subjects in both towns. The mean estimated long-term air-Mn exposure levels for total suspended particulate were 0.35 μg/m 3 (geometric mean [GM]) and 0.88 μg/m 3 (arithmetic mean [AM]) in East Liverpool (range: 0.014-6.32 μg/m 3) and 0.17 μg/m 3 (GM) and 0.21 μg/m 3 (AM) in Marietta (range: 0.03-1.61 μg/m 3). Modeled results compared well with averaged ambient air measurements from local air monitoring stations. Exposure to respirable Mn particulate matter (PM 10 ; PM <10 μm) was higher in Marietta residents. Implications: Few available studies evaluate long-term health outcomes from inhalational manganese (Mn) exposure in residential populations, due in part to challenges in measuring individual exposures. Local long-term air measurements provide the means to calibrate models used in estimating long-term exposures. Furthermore, this combination of modeling and ambient air sampling can be used to derive receptor-specific exposure estimates even in the absence of source emissions data for use in human health outcome studies.
Evaluation of Human Exposure to Ambient PM10 in the
The main goal of this study was to evaluate the magnitude of outdoor exposure to fine particulate matter (PM 10 ) potentially experienced by the population of metropolitan Mexico City. With the use of a geographic information system (GIS), spatially resolved PM 10 distributions were generated and linked to the local population. The PM 10 concentration exceeded the 24-hr air quality standard of 150 µg/m 3 on 16% of the days, and the annual air quality standard of 50 µg/m 3 was exceeded by almost twice its value in some places. The basic methodology described in this paper integrates spatial demographic and air quality databases, allowing the evaluation of various air pollution reduction scenarios. Achieving the annual air quality standard would represent a reduction in the annual arithmetic average concentration of 14 µg/m 3 for the typical inhabitant. Human exposure to particulate matter (PM) has been associated with mortality and morbidity in Mexico City; reducing the concentration levels of this pollutant would represent a reduction in mortality and morbidity and the associated cost of such impacts. This methodology is critical to assessing the potential benefits of the current initiative to improve air quality implemented by the Environmental Metropolitan Commission of Mexico City.
Exposure to Manganese: Health Effects on the General Population, a Pilot Study in Central Mexico
Environmental Research, 2001
To support a risk assessment of manganese exposure in two communities living within a manganese mining district a cross-sectional study was performed on a sample of the adult population of long-term residents. One community was exposed to a point source from an ore primary refining plant. Manganese is an essential mineral for human life. It is also the fourth in importance for industrial metal making. Data were collected on socioeconomic living conditions, emission sources, environmental media concentrations (air, water, soil, dust, food), respiratory symptomatology, and a neuropsychological examination (Mini-Mental Screening test, the Hooper Visual Organization test, the Ardila-Ostroski, and others). We examined 73 subjects (52 women), most of low socioeconomic status. Environmental air concentrations were 2 to 3 times higher than those in other urban concentrations. Manganese blood concentrations ranged from 7.5 to 88 μg/L, with a median concentration of 15, the upper quartile starting at 20 μg/L; the upper 10% was above 25 μg/L. Lead and manganese were highly correlated; there was an inverse relation to hemoglobin. Reduced levels of plasma lipid peroxidation were associated with blood manganese. Using multivariate logistic regression, we identified B-Mn as increasing the risk of deficient cognitive performance 12 times (Mini-Mental score of less than 17).
Perceived Health Risks of Manganese in the Molango Mining District, Mexico
Risk Analysis, 2010
A series of investigations, using an ecosystem approach to human health, have been conducted in the Molango Mining District in the state of Hidalgo, Mexico. Given that risk perception plays a key role in the public response to environmental exposures, it is important to recognize the perceived health risks of manganese (Mn). The aim of this study was to analyse the Mn risk perception by describing the attitudes of adult residents toward their communities, assessing the importance they give to environmental problems, including Mn, and their recognition of the links established between Mn and health-illness-death. A quantitative study based on interviewer-administered questionnaires was conducted. A sample of 402 residents was randomly selected from six communities at different distances from the mines and/or Mn processing plants. Descriptive statistics and logistic regression models were used to identify Mn risk perception predictors. The results show that roughly 30% of the residents identified mining activities and the resultant pollution as their most important concern. This proportion is greater in communities that have processing plants within them. More than 70% perceive a high Mn pollution regionally, but this proportion decreases when the residents attribute the pollution to their home area. More than 20% of the adults interviewed associated Mn exposure with their own illness, mainly "lungs" and "sight." Factors influencing Mn risk perception are community of residence, age group (41-60), and the report of having a chronic illness. The risk management plan for the mining district must take into account these differences to have a greater local impact.
Manganese survey in airborne particulate matter from a mining area at Hidalgo State, Mexico
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
A manganese (Mn) survey in airborne particulate matter from a mining area located in Hidalgo State (Mexico) was performed using PIXE. Deposits of Mn ore, ®rst discovered in 1959 and under continuous exploitation since 1962, are nowadays considered as one of the most important of their kind in the American Continent. Afterwards, local inhabitants have been under continuous overexposure to dusts and water highly enriched with Mn. Since no information was available about Mn content in airborne particulate matter in that area, especially in the respirable fraction PM 2X5 , airborne particles were collected simultaneously at two sites located on opposite sides of the rim of the mining valley, and along the line of prevailing local winds. The sample collection was performed on eight alternate days, taking two samples per day (day-time and night-time) at each sampling site, using Stacked Filter Units (SFUs) of the Davis design to separate particles into ®ne (PM 2X5) and coarse (PM 15) sizes. The samples were PIXE analyzed and the results of this study revealed that Mn content, in both ®ne and coarse fractions, were in excess of the general urban background level of 40 ng/m 3 (US Environmental Protection Agency, 1990) in more than 50% of the samples, which indicate severe environmental deterioration in the place under study.
American Journal of Industrial Medicine, 1987
In a plant producing manganese (Mn) oxides and salts, 11 different workplaces were identified. The current exposure to airborne Mn (total dust, personal sampling, n = 80) varied from 0.07 to 8.61 mg/m3. The geometric mean and median values amounted approximately to 1 mg/m3 and the 95th percentile was 3.30 mg/m3. The concentration of Mn in blood (Mn-B) in a group of 141 Mn-exposed male workers ranged from 0.10-3.59 pg/lOO ml compared to 0.04-1.31 pgl100 ml in a group of 104 control subjects. The ranges of the concentrations of Mn in urine (Mn-U) were 0.06-140.6 and 0.01-5.04 pg/g creatinine for the exposed and control groups, respectively. The average level of Mn-B in the Mn group was more than twice as high as in the control group (arithmetic mean, 1.36 vs 0.57 pg/lOO ml) and that of Mn-U was ten times higher in the Mn group (geometric mean, 1.56 vs 0.15 pg/g creatinine). The Mn-B level did not change significantly after 8 h of Mn exposure, whereas the Mn-U level dropped rapidly when exposure ceased (half-life less than 30 h).
Journal of Exposure Science and Environmental Epidemiology, 2006
Source apportionment may be useful in epidemiological investigation of PM health effects, but variations and options in these methods leave uncertainties. An EPA-sponsored workshop investigated source apportionment and health effects analyses by examining the associations between daily mortality and the investigators' estimated source-apportioned PM 2.5 for Washington, DC for 1988-1997. A Poisson Generalized Linear Model (GLM) was used to estimate source-specific relative risks at lags 0-4 days for total non-accidental, cardiovascular, and cardiorespiratory mortality adjusting for weather, seasonal/temporal trends, and day-of-week. Source-related effect estimates and their lagged association patterns were similar across investigators/methods. The varying lag structure of associations across source types, combined with the Wednesday/Saturday sampling frequency made it difficult to compare the source-specific effect sizes in a simple manner. The largest (and most significant) percent excess deaths per 5-95 th percentile increment of apportioned PM 2.5 for total mortality was for secondary sulfate (variance-weighted mean percent excess mortality ¼ 6.7% (95% CI: 1.7, 11.7)), but with a peculiar lag structure (lag 3 day). Primary coal-related PM 2.5 (only three teams) was similarly significantly associated with total mortality with the same 3-day lag as sulfate. Risk estimates for traffic-related PM 2.5 , while significant in some cases, were more variable. Soil-related PM showed smaller effect size estimates, but they were more consistently positive at multiple lags. The cardiovascular and cardiorespiratory mortality associations were generally similar to those for total mortality. Alternative weather models generally gave similar patterns, but sometimes affected the lag structure (e.g., for sulfate). Overall, the variations in relative risks across investigators/methods were found to be much smaller than those across estimated source types or across lag days for these data. This consistency suggests the robustness of the source apportionment in health effects analyses, but remaining issues, including accuracy of source apportionment and source-specific sensitivity to weather models, need to be investigated.