In June 1987, the U.S. Environmental Protection Agency (EPA) issued the revised national ambient air quality standards (NAAQS) for particulate matter (PK). The new regulation covers only particles 10 microns and less (PM10) rather than total suspended particulate (TSP). These particles are considered a health problem. The new standards limit concentrations of PM10 to 150 micrograms per cubic meter of air per day (24-hour average riot to be exceeded more than once a year) and 50 micrograms per cubic meter per day (24-hour average) averaged over the year. States have until March 31, 1988 to develop a state implementation plan (SIP), then 3 to 5 years to get into compliance. This standard could present a problem to cotton gins in some areas of the U.S., so know your local regulator.