Residence under an airport landing pattern as a factor in teratism.

An analysis of all Los Angeles County birth records for the years 1970, 1971, and 1972 reveals a higher incidence of reportable birth defects in those census tracts lying wholly or partly within the 90 dbA loudness contours under the landing pattern at Los Angeles International Airport than in the rest of the County. While not proving that noise is responsible for the increase in teratism, these results point to a potentially important physical environmental effect with significant public health implications.