(a) Scientific studies show that exposure to particulate matter from air pollution leads to significant human health problems, including: aggravated asthma; chronic bronchitis; reduced lung function; irregular heartbeat; heart attack; and premature death in people with heart or lung disease. Exposure to air pollutants that are carcinogens can also have significant human health consequences. For example, exposure to diesel exhaust is an established cause of lung cancer.
(b) Heart disease and stroke are the first and fourth leading causes of death in the U.S. respectively. Air pollution affects heart health and can trigger or contribute to heart attacks and strokes. One in three Americans has heart or blood vessel disease and is at higher risk from air pollution. Impacts on the lungs may take several forms. Short-term effects include deficits in lung function that can limit breathing, especially during exercise. Irritants from air pollution may cause airway constriction or chest tightening that is uncomfortable or limiting to normal activity. These changes in lung function are sometimes accompanied by underlying lung tissue inflammation which over the long term may lead to chronic lung disease. Exposure to air pollutants may be a contributing factor to leading causes of death recorded for San Francisco's population (ischemic heart disease; lung, bronchus and tracheal cancers; cerebrovascular disease; chronic obstructive pulmonary disease; hypertensive heart disease and lower respiratory infection).
(c) Persons living in close proximity to air pollution sources, such as freeways or busy roadways, have poorer lung functions and are more susceptible to developing asthma and other respiratory problems, compared with persons living at a greater distance from such sources. The California Air Resources Board's 2005 Land Use Guidance document, "Air Quality and Land Use Handbook: A Community Health Perspective," reviewed traffic-related air pollution studies and found that particulate matter pollution levels decrease by about 70 percent at 500 feet from freeways and high-traffic roadways, defined as urban roads with 100,000 vehicles/day or rural roads with 50,000 vehicles/day.
(d) Proximity to sources of air pollution increases exposure, and proximity to sources is established to be more common for the poor and for certain ethnic minorities.
(e) Consequently, health vulnerability varies among neighborhoods and populations within San Francisco, as measured by population health records of air pollution-associated hospital discharges and emergency room visits, and non-accident mortality. Health vulnerable populations are likely to have more significant health consequences from air pollutant exposure compared to populations that are less vulnerable.
(f) Existing regulatory control measures, often focused on new stationary sources of emissions and average regional air pollution concentrations, are not sufficient to address all local sources of exposure or disparities in exposure.
(g) "Sensitive Use" buildings have the highest proportion of individuals who are most vulnerable to air pollutant exposures.
(h) Available technologies exist to protect sensitive uses from air pollution health effects. Available and accepted air pollution modeling technology allows for the estimation of certain air pollutant concentrations for individual land parcels. Furthermore, available building ventilation and engineering technologies provide mechanisms to protect indoor environments from the infiltration of ambient air pollutants.
(Added by Ord. 281-08, File No. 080934, 12/5/2008; amended by Ord. 224-14
, File No. 140806, App. 11/7/2014, Eff. 12/7/2014)