Monitoring and Impact Assessment Approaches

Abstract

The discharge of heavy metal wastes has many obvious impacts on aquatic systems. There may be an increase in residue levels in water, sediments, and biota, decreased productivity, and increase in exposure of humans to harmful substances. Some of us are less aware of the effect of the environment on the fate of metals. As outlined in earlier chapters, such changes may decrease the toxicity of wastes, or at least remove them from immediate contact with humans. Given this diversity of effects, it is reasonable to suggest that environmental problems must be viewed in a broad context. Such diversity implies that methods used to manage, monitor, and assess heavy metal pollution should be equally complex. Although scientists often try to ignore social, political, economic, legal, and administrative forces, the success or failure of monitoring and assessment programs may also hinge on these factors (Tinkham, 1974). It has been estimated that total pollution control measures were responsible for the closure of 75 plants in the USA between 1971 and 1975, affecting 13,600 workers (Edmunds, 1978). In addition, total expenditures for pollution control will be $69 billion by 1984, thereby increasing the inflation rate by 0.3-0.5% (Edmunds, 1978). The magnitude of these figures emphasizes that the recommendations arising from monitoring and impact assessment programs must be relevant, timely and costeffective.