heart defects.” The NRDC also claims there's the potential for “Harm to the developing heart, brain and nervous system. Because even short-term exposures to these pollutants at critical moments of development can result in long-lasting harm.” Despite researcher's knowledge about the adverse health effects these pollutants can have on humans and the environment, it's challenging to fully understand the direct health impacts that are a result from fracking and assess the potential long-term health and environmental effects. This is because the oil and gas industry is legally protected from disclosing what is in the chemical compounds they use for fracking. “Policies are also lacking in requiring full health impact assessments to be required before companies are given the go-ahead to drill” Workplace safety In 2013 the United States the Occupational Safety and Health Administration (OSHA) and NIOSH released a hazard alert based on data collected by NIOSH that "workers may be exposed to dust with high levels of respirable crystalline silica (silicon dioxide) during hydraulic fracturing." Crystalline silica is the basic component of many minerals including sand, soil, and granite, but the most common form is quartz. Inhaling respirable crystalline silica can cause silicosis, lung cancer, autoimmune disorders, kidney disease, and can increase the risk of tuberculosis. It is also classified as a known human carcinogen. Out of the 116 air samples collected by NIOSH from 11 sites across 5 states, 47% showed silica exposures greater than the OSHA permissible exposure limit and 79% showed silica exposures greater than the NIOSH recommended exposure limit. NIOSH notified company representatives of these findings and provided reports with recommendations to control exposure to crystalline silica and recommend that all hydraulic fracturing sites evaluate their operations to determine the potential for worker exposure to crystalline silica and implement controls as necessary to protect workers. In addition to the hazard alert regarding exposure to respirable crystalline silica, OSHA released a publication entitled “Hydraulic Fracturing and Flowback Hazards Other than Respirable Silica,” in an attempt to further protect workers and better educate employers on a variety of additional hazards involved. The report includes hazards that may occur during transportation activities, rig-up and rig-down, mixing and injection, pressure pumping, flowback operations, and exposure to and VOCs. Transportation and rig-up/rig-down Serious injury and death can occur during the various transportation activities of hydraulic fracturing. Well sites are often small and congested, with many workers, vehicles, and heavy machinery.