Health Hazard Evaluation Report, HETA 2000-0363-2834, Pappas Chiropractic Center, Piscataway, New Jersey.
On July 14, 2000, the National Institute for Occupational Safety and Health (NIOSH) received a request from the owner of Pappas Chiropractic Center to conduct a health hazard evaluation (HHE) to evaluate possible exposure to mercury (Hg) at his chiropractic office in Piscataway, New Jersey. The requester had been diagnosed with Hg poisoning approximately six months before the request was received by NIOSH. The request was prompted by concerns that the chiropractic office may be the source of Hg exposure, even though there were no known sources of Hg in the office. In response to the request, NIOSH investigators conducted a site visit at Pappas Chiropractic Center on September 11-12, 2000. The environmental evaluation included a walk-through inspection of the building interior and exterior and full-shift area air samples to assess exposure to airborne Hg vapor and determine which, if any, offices contained a source of Hg. Direct-reading measurements for elemental Hg vapor were also collected throughout the office and outside. A sample of drinking water and a sample of stained wood chips from the exterior of the building were collected and submitted for analysis of Hg content. No visible sources of Hg were observed during the walk-through inspection of the interior and exterior of the building. There was evidence of water incursion in the unfurnished portion of the basement. The full-shift area air samples revealed no detectable concentrations of Hg vapor. The direct-reading measurements revealed airborne Hg concentrations ranging from no detectable concentration to 0.007 milligrams per cubic meter (mg/m3 ) throughout the first floor and basement of the office, and from no detectable concentrations to 0.008 mg/m3 outside the office. Approximately three to five consecutive measurements were taken at each location tested. Average Hg concentrations throughout the office ranged from no detectable concentration to 0.005 mg/m3 , whereas average Hg concentrations measured outside ranged from no detectable concentration to 0.004 mg/m3 . All of the individual and averaged instantaneous Hg vapor concentrations collected were well below the 0.1 mg/m3 ceiling limit stipulated by the Occupational Safety and Health Administration (OSHA) and NIOSH. The drinking water sample and the bulk sample of stained wood chips revealed no detectable concentrations of Hg. NIOSH investigators concluded that employees in the chiropractic office are not occupationally exposed to mercury. Recommendations for controlling methylmercury intake through dietary intake of fish and shellfish, as well as recommendations for dealing with future episodes of water incursion are presented in the report.