Health hazard evaluation report: HETA-2000-0305-2848, City of Long Beach Police Department, Long Beach, California.
In May 2000, the National Institute for Occupational Safety and Health (NIOSH) received a request for a health hazard evaluation (HHE) from a representative of the International Association of Machinists and Aerospace Workers (IAM) Local 1930. The health concerns were genital numbness, sexual dysfunction, and feet problems in the Marine Bicycle patrol, Long Beach Police Department, Long Beach, California. From July 10 to 22, 2000, NIOSH researchers visited the City of Long Beach, California, to evaluate the Marine Bicycle patrol Officers and the possible health effects associated with biking. Twenty-nine biking officers participated in at least part of the study. Five non-biking men from the Long Beach area were used as the comparison group. Fourteen of the fifteen (93 percent) bikers responding to question on genital numbness indicated that at times they experienced numbness in their buttocks, scrotum, testicles , or penis during or after riding their bicycles. This numbness occurred after 10 minutes to 3 hours of riding and lasted from 5 minutes to 24 hours. Blood hormone levels and semen quality were normal in the officers providing samples. The male study participants were asked to wear a Rigscan erection monitoring device for 2 nights. The number of sleep erections was not affected indicating the basic neurophysiology of erectile function was intact I biking officers. However, measure of erection quality were lower in the biking officers. The percent of the sleeping time a man had an erection was statistically reduced (p=0.0097) in the biking police (26.2 percent) compared to men (42.8 percent) not riding bicycles. As the measured pressure between the officer and the bicycle seat increased, the percent sleeping time the individual had an erection was decreased. Similarly, as the average number of hours per day an officer was on his bike and the average number of days a week the officer rode his bike increased, the percent sleeping time with an erection decreased. This study indicates that the pressure between the biking officer and the bicycle seat is related to numbness in the genitals and subclinical impairment of erectile function. Blood hormone levels and semen quality were normal in the officers providing samples. Recommendations to minimize or eliminate these specific problems reported by biking officers include minimizing pressure to the perineum from the bicycle seat nose. This can be achieved by taking rest periods off of the bicycle saddle and ensuring proper bicycle fit. The police department is encouraged to investigate the feasibility of using bicycle seats without a nose or other extension.