The World Health Organisation and the prevention of deafness and hearing impairment caused by noise.
The WHO Programme for Prevention of Deafness and Hearing Impairment (PDH) is especially targeted at developing countries where there is a serious lack of accurate population-based data on the prevalence and causes of deafness and hearing impairment, including noise-induced hearing loss. However, opportunities exist for prevention of noise-induced hearing loss by primary, secondary and tertiary means and it is necessary for countries to measure the size of the problem and adopt strategies for its prevention. The World Health Assembly has passed two resolutions in relation to PDH, in 1985 and 1995. They affirmed that much deafness and hearing impairment is avoidable or remediable and that the greatest needs for the problem are in developing countries. The 1995 resolution estimated that there are 120 million persons with disabling hearing difficulties worldwide and urged member states to set up National Programmes for the prevention of deafness and hearing impairment, with the technical assistance of WHO. WHO-PDH addresses problems in this field of major public health importance which are amenable to intervention, giving priority to the poorest developing countries. These problems include ototoxicity, chronic otitis media, noise damage to hearing, inherited and congenital causes, and the provision of appropriate affordable hearing aid services. A fundamental requirement for the development of a National Plan and choice of preventive strategy for a National Programme is accurate, population-based data on the prevalence and causes of the problem. The PDH programme has developed a standardised Ear Disease Assessment Protocol to enable countries to conduct national surveys rapidly. A National Programme will require a set of integrated strategies to prevent deafness and hearing impairment. The PDH programme has already addressed two such causes, ototoxic drugs and chronic otitis media and will shortly produce guidelines for implementation of these strategies within the context of primary health care. The most recent meeting organised by the PDH programme at WHO, in the series on strategies for prevention, was on the prevention of noise-induced hearing loss, held in Geneva in October 1997. The participants concluded that exposure to excessive noise is the major avoidable cause of permanent hearing impairment worldwide. Noise-induced hearing loss is the most prevalent irreversible industrial disease, and the biggest compensatable occupational hazard. In developing countries, occupational noise and urban, environmental noise are increasing risk factors for hearing impairment. The meeting recommended that all countries should implement National Programmes for the Prevention of noise-induced hearing loss, integrated with Primary Health Care, and including elements on health promotion, and measures to reduce noise sources and introduce legislation and effective hearing conservation. There is an urgent need to obtain more, accurate epidemiological data on the problem, especially in developing countries. More research is needed on basic mechanisms and means of prevention.
Smith
Andrew W.
AW
Prevention of Deafness and Hearing Impairment (PDH), World Health Organization, CH-1211 Geneva 27, Switzerland, Email: smithaw@who.ch