Natural rubber latex-related occupational asthma: Association with interventions and glove changes over time

Background Exposure to natural rubber latex (NRL) has been recognized as a cause of occupational asthma (OA), especially among health care workers (HC Ws) associated with use of gloves. Little or no population-based data are a vailable which chart the changes over time in the number of cases of OA as this problem was increasingly recognized and then interventions instituted. Methods We obtained the numbers of allowed asthma claims with exposure to l atex by year in the province of Ontario, Canada from the Ontario Work-place Safety, and Insurance Board; details of the cases from the largest teachin g hospital were reviewed. Interventions included: (1) in 1996, the Board re commended in its focus for accommodation of sensitized workers, the reducti on of aerosols of latex proteins and that hospital facilities use powder-fr ee, low-protein or nonlatex gloves; and (2) hospitals instituted latex poli cies and glove changes at various dates. For example, at the largest teachi ng hospital, interventions included education and voluntary medical surveil lance in 1994; substitution of low protein, "powder-free" NRL gloves for no n-sterile powdered gloves in 1995; and replacement of powdered sterile NRL gloves by lower protein, "powder-free" NRL gloves in 1997. Results Through 1999, there were 60 allowed claims for asthma in Ontario wi th exposure to latex; of these 49 (82%) were among HCWs. The number of clai ms among HCWs changed from 0 to 2 per year zip to 1990; increased to 7 to I I per year between 1991-1994; and declined to 3 per year in 1995-1996 and 1 to 2 per year in 1997-1999. Of the ten institutions having two or more OA latex claims, all claims occurred in 1996 or earlier at 8 (80%). At the la rgest hospital, there were five accepted claims with year of diagnosis in 1 993 (1 case), 1994 (3 cases), and 1995 (1 case). Conclusions These findings suggest that, despite the effect of increasing r ecognition, the introduction of gloves with reduced powder and/or protein, as well as other interventions have been associated temporally with decline s in the number of cases of latex OA. (C) 2001 Wiley-Liss, Inc.