Salim Vohra
What is Health Impact Assessment, Environmental Medicine

publication: book chapter

Health Impact Assessment

Chapter 63, Environmental Medicine, Hodder Arnold, 2010

Setting, implementing and maintaining health-based guidelines has proved very important in protecting human health. The approach has, however, some important limitations. First, it sometimes happens that, where pollutant levels are lower than guideline values, it is considered acceptable to allow a drift upwards towards those guidelines; or, in an equivalent manner, that policies or developments that imply an increase in pollution are considered acceptable as long as guideline levels are not exceeded. This ignores the possibility of effects at concentrations below guidelines, a problem especially with pollutants that have no threshold at population level.

Second, health-based guidelines do not per se take account of the difficulties and costs involved in achieving them, and therefore they are not amenable for comparing the costs and benefits of a new proposal. Third, measures to reduce pollution to conform with limits may have other unintended consequences, including health impacts mediated through other environmental or social determinants of health.

Attempts to overcome these limitations have contributed to the development and increased use of other methods of using science to inform the development of policy. One such set of methods is called HIA.