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Latest on-line papers from the SEGH journal: Environmental Geochemistry and Health
- Geospatial association between adverse birth outcomes and arsenic in groundwater in New Hampshire, USA 2014-10-19
There is increasing evidence of the role of arsenic in the etiology of adverse human reproductive outcomes. Because drinking water can be a major source of arsenic to pregnant women, the effect of arsenic exposure through drinking water on human birth may be revealed by a geospatial association between arsenic concentration in groundwater and birth problems, particularly in a region where private wells substantially account for water supply, like New Hampshire, USA. We calculated town-level rates of preterm birth and term low birth weight (term LBW) for New Hampshire, by¬†using data for 1997‚Äď2009 stratified by maternal age. We smoothed the rates by¬†using a locally weighted averaging method to increase the statistical stability. The town-level groundwater arsenic probability¬†values are from three GIS data layers generated by the US Geological Survey: probability of local groundwater arsenic concentration >1¬†¬Ķg/L, probability >5¬†¬Ķg/L, and probability >10¬†¬Ķg/L. We calculated Pearson‚Äôs correlation coefficients (r) between the reproductive outcomes (preterm birth and term LBW) and the arsenic probability¬†values, at both state and county levels. For preterm birth, younger mothers (maternal age <20) have a statewide r¬†=¬†0.70 between the rates smoothed with a threshold¬†=¬†2,000 births and the town mean arsenic level based on the data of probability >10¬†¬Ķg/L; for older mothers, r¬†=¬†0.19 when the smoothing threshold¬†=¬†3,500; a majority of county level r values are positive based on the arsenic data of probability >10¬†¬Ķg/L. For term LBW, younger mothers (maternal age <25) have a statewide r¬†=¬†0.44 between the rates smoothed with a threshold¬†=¬†3,500 and town minimum arsenic concentration based on the data of probability >1¬†¬Ķg/L; for older mothers, r¬†=¬†0.14 when the rates are smoothed with a threshold¬†=¬†1,000 births and also adjusted by town median household income in 1999, and the arsenic values are the town minimum based on probability >10¬†¬Ķg/L. At the county level for younger mothers, positive r values prevail, but for older mothers, it is a mix. For both birth problems, the several most populous counties‚ÄĒwith 60‚Äď80¬†% of the state‚Äôs population and clustering at the southwest corner of the state‚ÄĒare largely consistent in having a positive r across different smoothing thresholds. We found evident spatial associations between the two adverse human reproductive outcomes and groundwater arsenic in New Hampshire, USA. However, the degree of associations and their sensitivity to different representations of arsenic level are variable. Generally, preterm birth has a stronger spatial association with groundwater arsenic than term LBW, suggesting an inconsistency in the impact of arsenic on the two reproductive outcomes. For both outcomes, younger maternal age has stronger spatial associations with groundwater arsenic.
- The arsenic contamination of rice in Guangdong Province, the most economically dynamic provinces of China: arsenic speciation and its potential health risk 2014-10-07
Rice is a staple food in China, but it may contain toxic heavy metals. Hence, the concentrations of arsenic (As) species (AsIII, AsV, MMA and DMA) were evaluated in 260 rice samples from 13 cities of Guangdong Province, the most economically dynamic provinces of China. The levels of sum concentrations of As species in rice samples varied from non-detect to 225.58¬†ng¬†g‚ąí1, with an average value of 57.27¬†ng¬†g‚ąí1. The mean concentrations of the major As species detected in rice samples were in the order AsIII (34.77¬†ng¬†g‚ąí1)¬†>¬†AsV (9.34¬†ng¬†g‚ąí1)¬†>¬†DMA (8.33¬†ng¬†g‚ąí1)¬†>¬†MMA (4.82¬†ng¬†g‚ąí1). The rice samples of Guangdong Province were categorized as inorganic As type. Significant geographical variation of As speciation existed in rice samples of 13 cities of Guangdong Province by chi-square test (p¬†<¬†0.05). The average human weekly intakes of inorganic As via rice consumption in Guangdong Province, southern China, were 1.91¬†¬Ķg¬†kg‚ąí1 body weight. Hazard quotients of total As via rice consumption of adults in 13 cities ranged from 0.06 to 0.30, indicating the As contents in rice from Guangdong Province had no potential adverse impact on human health.
- Selected papers from the 29th SEGH Conference on Environmental Geochemistry and Health 2014-10-01