Health hazard evaluation report: HETA-2007-0216-3056, evaluation of Histoplasmosis concerns at a United States Post Office, Apple Valley, California.
On April 17, 2007, NIOSH received a request from NALC for an HHE on behalf of workers at the USPS in Apple Valley, California. NALC representatives filed the HHE request because workers at the post office were potentially exposed to pigeon droppings from pigeons roosting on the roof and in the building's HVAC units. Some workers reported experiencing dizziness, breathing difficulties, cough, and weakness, and were concerned that these symptoms resulted from exposure to H. capsulatum, a fungus that causes histoplasmosis, a fungal lung infection. A dead-animal odor in the building was reported by employees and added to their concerns. The NALC specifically asked that NIOSH conduct or recommend medical testing for all AVPO employees to determine whether these symptoms were related to exposure to H. capsulatum, and conduct any additional site evaluations deemed necessary to ensure the health and safety of the postal workers. On July 11-13, 2007, NIOSH representatives made a site visit to the AVPO. NIOSH investigators held opening and closing conferences with union representatives (NALC), management of AVPO, the safety manager, representatives from the USPS San Diego district office, and an industrial hygiene contractor who previously performed environmental sampling. We took IEQ measurements (temperature, RH, and CO2) and held confidential medical interviews with USPS employees. We also reviewed available environmental testing reports and maintenance records. We found no direct relationship between current health symptoms reported by AVPO employees and specific occupational or environmental exposures. Perceived odor and building ventilation issues likely contributed to these symptoms. We found that the potential for employees to contract histoplasmosis was low and this potential was further minimized by cleaning and installing nets around the HVAC units. We do not recommend testing AVPO employees for histoplasmosis. However, if individual employees feel that they should be tested due to their symptoms, they should discuss their symptoms and concerns with their physician. At the time of our investigation, we found comfort parameters at the post office to be within acceptable guidelines recommended by ASHRAE except for elevated CO2 levels in some work areas, possibly indicating inadequate outdoor air intake or uneven mixing of air. All pigeon fecal matter had been cleared from the units we examined and, overall, the bird netting appeared intact. Although we saw two bird feathers in one of the HVAC units, we found no evidence that birds were entering or still living in the unit.
Region-9; Hazard-Unconfirmed; Respiratory-system-disorders; Respiratory-infections; Pigeon-breeders-disease; Pulmonary-system-disorders; Ventilation; Ventilation-systems; Indoor-air-pollution; Air-quality; Postal-employees; Indoor-environmental-quality;
Author Keywords: Postal Service; histoplasmosis; pigeons; fecal matter; postal workers; indoor environmental quality; IEQ; ventilation; odors