HOW THE MOVE FROM PM_(10) TO PM_(25) IS SIGNIFICANT TO ANIMAL PRODUCTION

摘要

The atmospheric concentration of compounds is regulated through the Clean Air Act (Public Law 80-159, 1955). This Act and its subsequent amendment specifically established National Ambient Air Quality Standards (NAAQS) for six compounds: carbon monoxide, ozone, particulate matter (PM), sulfur dioxide, nitrogen oxides, and hydrocarbons. The PM standard initially was based to control total suspended PM (particles up to 40 μm in diameter. In 1978, the standard was revised to regulate inhalable particles, or particles that can deposit in the respiratory tract and therefore have greater potential for causing adverse health effects (PM_(10) -- particulate matter with an aerodynamic diameter less than or equal to a nominal ten micrometers). Recent federal review of the NAAQS resulted in a new standard for PM. The new proposed standard is for PM_(2.5). The rationale behind having a PM standard relates to the impact of PM on health. The NAAQS were developed in order to protect the health of the population, particularly those thought to be sensitive.