Measurement of atmospheric vinyl chloride.

Methods for atmospheric vinyl chloride measurement have been reviewed. The lowest detection limits and most specific measurement are achieved by scrubbing atmospheric samples with activated charcoal, desorbing the vinyl chloride, and assaying it by gas chromatography (GC). NIOSH currently recommends collecting samples using tubes packed with 150 mg of coconut shell charcoal, desorbing with carbon disulfide, and analyzing by GC equipped with flame-ionization detection (FID); the method is capable of detecting less than 1 ppm vinyl chloride and has an apparent recovery of abo the ppb level with no loss of accuracy or precision. Some field methods, such as infrared analysis and conductivity measurement, are capable of detecting 1 ppm or lower but are subject to interferences by other contaminants; th-y could be useful for evaluating sources of vinyl chloride leaks and for continuous monitoring. Permeation tubes are superior to gravimetric or volumetric methods for generating atmospheres of known vinyl chloride concentration.

Public attitude toward pesticides. A random survey of pesticide use in Allegheny County, Pa.

Pesticide use was examined by means of a random survey in Allegheny County, Pa., in October and November 1973. The objectives included gaining insight into the need for a new community pesticide program and estimating its public acceptance. The 110 survey sites were grouped as single-family dwellings, commercial and recreational lawns, institutions, farms, rights-of-way, and wasteland. In the single-family dwellings, most householders (85 percent) used a pesticide in the previous 12 months, usually an aerosol insecticide (76 percent) or herbicide (55 percent). Their pesticide selections were most often based on advertisements of availabel products. A high percentage lacked either the interest or the knowledge of the information on the pesticide's label. No observation in this or any other study supports the need for a new special program in pesticides or indicates that a substantial segment of the public would use its services. The main users of "hard" pesticides were the golf courses, rights-of-way, and one farm-nursery. The rights-of-way used chemicals only for vegetation control. Utilities and railroads contracted with pesticide companies for this work. Municipal users applied pesticides recommended by dealers. The golf courses and a farm-nursery used a broad range of fungicides, insecticides, and herbicides, which they selected because of information received from the Pennsylvania Extension Service and professional organizations.