Reversing the trend towards an overall increase in noise pollution through a combination of noise emission and noise immission control measures.
These comprise numerous measures such as a common noise classification scheme, the definition of a standard index and a standard method for calculating noise exposure levels, the introduction of noise-monitoring, and noise-zoning.
Agenda 21 recommends the development of criteria for maximum permitted safe noise exposure levels and promotion of noise assessment and control as part of environmental health programmes.
Human health and wellbeing can be improved by reducing exposure to noise through introducing targets that take into account recommendations contained in WHO guidelines on noise (1980, 1993, 1999), including concern for specific environments where quietness should prevail (residential areas, schools, hospitals), environments where the noise of transport activities should be reduced (areas within range of airports, highways, railways, terminals, petrol stations) and sensitive time periods (nights, evenings, weekends).
This strategy features in the framework of Agenda 21 as formulated at UNCED (Rio de Janeiro, 1992), now coordinated by the United Nations Commission on Sustainable Development and implemented through national and local authorities.
Keeping night-time sound levels in residential areas within WHO recommended night-time values and, where these values are currently exceeded, striving to reduce them to recommended sound levels.
Protecting existing quiet parkland and conservation areas and promoting quietness in such areas, by keeping down the ratio of noisy transport activities relative to background sound levels in these areas.