Health Hazard Evaluation Report: HETA-2007-0257-3082, Brigham and Women's Hospital, Boston, Massachusetts, May 2009. UV-C Exposure and Health Effects in Surgical Suite Personnel

摘要

On May 18, 2007, NIOSH received an HHE request from the Director of Environmental Affairs at Brigham and Womens Hospital in Boston, Massachusetts. The request indicated that some orthopedic surgical staff were concerned about unspecified skin and eye symptoms that they attributed to germicidal UV-C radiation produced by ceiling-mounted UV lamps in orthopedic operating rooms. On October 1-3, 2007, we met with employee, union, and management representatives, toured the orthopedic operating suites, measured OR staff UV-C exposure with personal dosimeters during a surgical procedure, measured UV-C exposure beneath PPE items, and reviewed hospital VGI policies. We also conducted confidential employee interviews and reviewed medical records of BWH orthopedic OR staff. On December 10, 2007, personal dosimetry was conducted during orthopedic procedures in three ORs. Orthopedic OR staff UV-C exposures, measured at shoulder height beneath a scrub shirt and warm-up jacket or surgical gown (i.e., two layers of PPE), were well below the NIOSH REL during 94- to 195-minute periods when UVGI was in use. Dosimeters placed outside PPE at shoulder height recorded UV-C doses that were 6 to 28 times greater than the REL. PPE assessment for UV-C attenuation identified surgical masks and a reinforced gown that did not reduce irradiance below 0.2 microW/cm2. Other hospital-approved headwear and combinations of protective garments such as scrubs and warm-up jackets evaluated during this HHE attenuated irradiance to below 0.2 microW/cm2. Five of 14 orthopedic OR nurses and surgical technicians interviewed reported possible UVGI-related symptoms; three had eye irritation, one had actinic keratoses (a precursor to skin cancer), and one had both eye irritation and actinic keratoses. Most OR staff reported lack of training in UV-C hazards and did not wear sunscreen at work for a variety of reasons, while some found PPE cumbersome and uncomfortable. None of the eye and skin screening examinations done by the hospital since 2003 documented changes that were attributed to UV-C exposure. However, of the 28 OR nurses and surgical technicians who participated in the examination, 3 were diagnosed with melanoma, 3 with basal cell carcinoma, and 5 with actinic keratoses. Although medical screening exams of OR employees exposed to UV-C lamps did not document skin (redness) or eye (photokeratitis) changes directly related to UV-C exposure, employee reports of skin redness and eye discomfort after UV-C exposure may indicate that overexposures have occurred. The skin cancers and actinic keratoses found on employee skin exams are known to be caused by UV exposure from the sun. There is not enough information in the scientific literature to know if UV-C exposure causes cancer in humans, although evidence for cancer in animals exists. However, UV-C radiation has been classified as reasonably anticipated to be a human carcinogen by the NTP. Infection control considerations aside, substitution of other infection control technologies such as laminar airflow is the preferred way to eliminate the UV hazard in ORs. In addition to eliminating the source of the hazard, substitution also eliminates the need for UV-C hazard awareness training, PPE training, ongoing supervision of PPE use, inspection and evaluation of PPE, and medical surveillance. Since the last NIOSH site visit in December 2007, BWH has discontinued the use of UVGI for intraoperative infection control.