Mercury pollution from small-scale gold mining poses a serious threat to the global and local environment. Recycling of mercury for small-scale miners has been introduced over decades in Tanzania with little success. The environmen- tally benign borax gold extraction method invented more than thirty years ago in the Philippines and presently used by more than thirty thousand Philippine miners has proved to work on the gold ores in Chunya and Singida gold districts of Tanzania. By using borax instead of mercury the miners reduce the risk of polluting the environment and spoil their health for generations. The most convincing argument for the miners to change to borax is that they can increase their gold recovery up to fifty percent without need for investing in new equipment and without much more work on proc- essing.
Identification and systematic assessment of hazardous wastes sites in low and middle-income countries has lagged. Hazardous waste problems are especially severe in lower income Asian countries where environmental regulations are non-existent, nonspecific or poorly enforced. In these countries extensive unregulated industrial development has created waste sites in densely populated urban areas. These sites appear to pose significant risks to public health, and especially to the health of children.
To assess potential health risks from chemical contamination at hazardous waste sites in Asia, we assessed 679 sites. A total of 169 sites in 7 countries were classified as contaminated by lead. Eighty- two of these sites contained lead at levels high enough to produce elevated blood lead levels in surrounding populations.
To estimate the burden of pediatric lead poisoning associated with exposure to lead in soil and water at these 82 lead-contaminated sites, we used standard toxicokinetic models that relate levels of lead in soil and water to blood lead levels in children. We calculated blood lead levels, and we quantified losses of intelligence (reductions in IQ scores) that were attributable to lead exposure at these sites.
We found that 189,725 children in the 7 countries are at risk of diminished intelligence as a consequence of exposure to elevated levels of lead in water and soil at hazardous waste sites. Depending on choice of model, these decrements ranged from 4.94 to 14.96 IQ points. Given the restricted scope of this survey and the conservative estimation procedures employed, this number is almost certainly an underestimate of the full burden of disease.
Exposure to toxic chemicals from hazardous waste sites is an important and heretofore insuffi- ciently examined contributor to the Global Burden of Disease.
We evaluate air Pb emissions and latent aggravated assault behavior at the scale of the city. We accomplish this by regressing annual Federal Bureau of Investigation aggravated assault rate records against the rise and fall of annual vehicle Pb emissions in Chicago (Illinois), Indianapolis (Indiana), Minneapolis (Minnesota), San Diego (California), Atlanta (Georgia), and New Orleans (Louisiana). Other things held equal, a 1% increase in tonnages of air Pb released 22 years prior raises the present period aggravated assault rate by 0.46% (95% CI, 0.28 to 0.64). Overall our model explains 90% of the variation in aggravated assault across the cities exam- ined. In the case of New Orleans, 85% of temporal variation in the aggravated assault rate is explained by the annual rise and fall of air Pb (total = 10,179 metric tons) released on the population of New Orleans 22 years earlier. For every metric ton of Pb released 22 years prior, a latent increase of 1.59 (95% CI, 1.36 to 1.83, p b 0.001) aggravated assaults per 100,000 were reported. Vehicles consuming fuel containing Pb addi- tives contributed much larger quantities of Pb dust than generally recognized. Our findings along with others predict that prevention of children’s lead exposure from lead dust now will realize numerous societal bene- fits two decades into the future, including lower rates of aggravated assault.
Background: Continuous exposure to many chemicals, including through air, water, food, or other media and products results in health impacts which have been well assessed, however little is known about the total disease burden related to chemicals. This is important to know for overall policy actions and priorities. In this article the known burden related to selected chemicals or their mixtures, main data gaps, and the link to public health policy are reviewed.
Approaches to systematic assessment if environmental exposures posed at hazardous waste sites in the developing world: The Toxics Sites Identification Program
Borax: Summary of health risks associated with using borax in artisanal and small-scale gold mining