Air pollution would render the San Joaquin Valley uninhabitable if its population density equaled that of the Los Angeles Basin, Stewart Wilson, a staff analyst with the Fresno County Air Pollution Control District, declared. The valley’s topography, weather and air circulation combine for “the worst possible conditions for air pollution formation,” Wilson told a seminar at Fresno State University in which social and economic effects of the region’s air pollution were examined. The entire valley violates state and federal ozone standards, and levels in some areas are worse than much larger cities such as New York, Houston and Philadelphia, the state Air Resources Board said. Ed Yotter, a board staff member, said all pollutants, except for fine dust particles, will remain constant or decline in the next few years, mainly due to the state’s stringent pollution control requirements on cars. But after the year 2000, “all pollutants will be increasing in all regions unless additional measures are taken,” he said.