Technical Assistance Report No. TA-79-026-978, U.S. Border Crossing Stations, Laredo, Texas.
Worker exposures to airborne contaminants were surveyed on September 29 to October 1, 1979 at United States Border Crossing Stations (SIC- 4784) in Laredo, Texas. The evaluation was requested by the United States Department of Agriculture, Animal and Plant Health Inspection Service, on behalf of an unspecified number of inspectors. Noise levels and airborne contaminant concentrations were measured, and preshift and postshift carboxyhemoglobin (COHb) values were determined. Concentrations of carbon-monoxide (630080), lead (7439921), ozone (10028156), benzene (71432), sulfuric-acid (7664939), particulates, sulfur-dioxide (7446095), and nitrogen- dioxide (10102440) were below respective OSHA standards of 50 parts per million (ppm), 0.05 milligram per cubic meter (mg/cum), 0.1ppm, 32mg/cum ceiling concentration, 10mg/cum, 10mg/cum, 5ppm, and 5ppm ceiling concentration. Noise levels were less than 90 decibels relative to the A-weighted scale COHb values increased during the work shift. The authors conclude that no hazardous exposure exist for the inspectors. Recommendations are included for inspection of the heating and air conditioning equipment at the inspection stations, increasing the distance between vehicles awaiting inspection and the inspection booth, and job rotation periods of 30 minutes.
Hazard Evaluations and Technical Assistance Branch, NIOSH, Cincinnati, Ohio, 17 pages, 14 references