The increase in fracking from 2009 led to a drop in natural gas prices that made natural gas become more competitive with coal. This analysis estimates coal generation decreased as a result by 28%, which led to an average reduction of 4% in air pollution yielding positive health benefits. However, this is only the case in the US and may not be applicable to other countries with lower coal generation rates. Impacts on human health The evidence about the potential detrimental health effects as a result of fracking have been mounting; threatening the well-being of humans, animals and our environment. These pollutants, even when exposed to at low levels, can lead to a multitude of both short and long term symptoms. Many of these health consequences start off as acute issues, but due to long term exposure turn into chronic diseases. Volatile organic compounds and diesel particulate matter, for example, result in elevated air pollution concentrations that exceed EPA guidelines for both carcinogenic and noncarcinogenic health risks. According to the Natural Resources Defense Council (NRDC), cancer-causing pollutants such as benzene, formaldehyde, and diesel have been found in the air near fracking sites. These pollutants generate wastewater, which is linked to groundwater contamination, threatening nearby drinking water and causing concern for anyone who is exposed. Studies done by the National Institute for Occupational Safety and Health (NIOSH) found that “Fracking also uses crystalline silica, which is a type of sand that’s used to keep the fractures open.” Exposure to this, along with dust and other air pollutants produced from fracking, can cause respiratory problems. One of the most common types of pollutants released into the air from fracking is methylene chloride, thought to be one of the most concerning due to its potentially severe impact on neurological functioning. Once again, the impacts can range from acute and moderate to chronic and more severe. Dizziness, headaches, seizures and loss of consciousness have all been observed in people exposed to this deadly chemical. Longer-term impacts tend to present themselves in areas such as memory loss, lower IQ and delayed mental development. Expecting mothers are also being cautioned. Polycyclic aromatic hydrocarbons released into the air from fracking has been linked to potential reproductive problems. A study conducted by the Colorado Department of Environmental and Occupational Health found that “Mothers who live near fracking sites are 30 percent more likely to have babies with congenital