The definition to the term environmental issues with respect to urban areas has become complicated and muddled; however, when referring to environmental issues, we are mostly referring to "damage to the physical environment" that is mostly caused by people and usually has "harmful consequences for human welfare" (Satterthwaite, "Understanding Issues: Answers to common questions concerning the urban environment").
According to Satterthwaite, the following are four major environmental issues in urban areas:
- households having inadequate water supply. Inadequate household water supply can lead to household sanitation issues and indoor air pollution, both of which will harm human welfare. Indoor air pollution refers to any "toxic contaminants" found inside of a home or building as opposed to out of doors ("What is the Definition of Indoor Air Pollution?"). While chemicals contribute a great deal to indoor air pollution levels, so do "biological agents" as a result of lack of sanitation, such as "pet dander, dust and mold" ("What is the Definition").
- City-wide and regional environmental problems. City-wide environmental problems can include outdoor air pollution, poor waste management, and water pollution, including pollution in lakes, rivers, and along the coast.
- Extra-urban environmental problems. What is known as "ecological disruptions" can significantly affect both outside of the urban area and the actual urban area. Ecological disruptions include, among others, changes to natural habitats, changes to ecosystems due to loss of predators, and increases in farming ("Ecological Disruptions"). Depletion of natural resources will also severely impact both the extra-urban and urban areas. Finally, increases in carbon dioxide will impact both the extra-urban and urban areas by resulting in acid rain and greenhouse gas emissions.
- "Regional or global environmental burden." A regional or global environmental burden is considered anything hazardous that can effect human well-being on both a regional or global scale respectively ("Varanasi's Environmental Burdens"). These burdens will be produced by activity outside of an urban area but will also significantly impact people within the urban area. Such environmental burdens can include regional and global outdoor air pollution, regional and global water pollution, and poor regional and global waste management ("Varanasi's Environmental Burdens").
When it comes to city planning, many strategies can be implemented to try and mitigate some of the above environmental issues. Mitigating the problem of indoor air pollution is important for eliminating health problems and consequential health care coverage problems. Indoor air pollution can be considered emissions from building materials, "building maintenance products, [and] personal care products" ("Sustainability Plan: Air Quality"). Even electrical equipment can emit indoor air pollutants, electrical equipment such as computers and copy machines. Finally, ventilation systems within buildings play a significant role in either reducing or promoting indoor air pollution.
It has been suggested that cities can nominate an "air quality coordinator" to focus on monitoring air quality and implementing policies to improve air quality. Among the things an air quality coordinator can do is lobby the federal government to raise prices of air-pollution producing products to reflect the environmental and health costs of the products. An air quality coordinator can also lobby lawmakers to tax air-pollution producing products ("Sustainability Plan: Air Quality").