improvement of environmental quality. Environmental law includes the network of treaties, statutes, regulations, common and customary laws addressing the effects of human activity on the natural environment. Information from epidemiology, toxicology, and exposure science can be combined to conduct a risk assessment for specific chemicals, mixtures of chemicals or other risk factors to determine whether an exposure poses significant risk to human health (exposure would likely result in the development of pollution-related diseases). This can in turn be used to develop and implement environmental health policy that, for example, regulates chemical emissions, or imposes standards for proper sanitation. Actions of engineering and law can be combined to provide risk management to minimize, monitor, and otherwise manage the impact of exposure to protect human health to achieve the objectives of environmental health policy. Concerns Environmental health addresses all human-health-related aspects of the natural environment and the built environment. Environmental health concerns include: Air quality, including both ambient outdoor air and indoor air quality, which also comprises concerns about environmental tobacco smoke. Biosafety. Disaster preparedness and response. Climate change and its effects on health. Environmental racism, wherein certain groups of people can be put at higher risk for environmental hazards, such as air, soil, and water pollution. This often happens due to marginalization, economic and political processes, and ultimately, racism. Environmental racism disproportionately affects different groups globally, however generally the most marginalized groups of any given region/nation. Food safety, including in agriculture, transportation, food processing, wholesale and retail distribution and sale. Hazardous materials management, including hazardous waste management, contaminated site remediation, the prevention of leaks from underground storage tanks and the prevention of hazardous materials releases to the environment and responses to emergency situations resulting from such releases. Housing, including substandard housing abatement and the inspection of jails and prisons. Childhood lead poisoning prevention. Land use planning, including smart growth. Liquid waste disposal, including city waste water treatment plants and on-site waste water disposal systems, such as septic tank systems and chemical toilets. Medical waste management and disposal. Noise pollution control. Occupational health and industrial hygiene. Radiological health, including exposure to ionizing radiation from X-rays or radioactive isotopes. Recreational water illness prevention, including from swimming pools, spas and ocean and freshwater bathing places. Safe drinking water. Solid waste management, including landfills, recycling facilities, composting and solid waste transfer stations. Toxic chemical exposure whether in consumer products, housing, workplaces, air, water or soil.