1.1 BACKGROUND OF THE STUDY
An environmental hazard is a substance, state or event which has the potential to threaten the surrounding natural environment and/or adversely affect people’s health. This term incorporates topics like pollution and natural disasters such as storms and earthquakes (Wikipedia, 2017).
Environmental Hazards was conceived before the start of the International Decade for Natural Disaster Reduction in 1990. During the fifteen years that have since elapsed, our understanding of the environment and the study of hazards have both advanced rapidly – certainly, and unfortunately, more rapidly than our ability to reduce disaster impacts. Consequently, the death and destruction from large disasters continues to increase. As the third millennium begins to unfold, there is also an awareness that environmental hazards are not only caught up in the ongoing processes of global change but are themselves an integral part of that scene. Indeed, many of the trends observed today – resource depletion, globalization, spread of material wealth, reliance on technology – can contribute to the toll of disaster on people and what they value in all nations irrespective of their state of human and economic development (Keith, 2004).
Environmental Hazards remains an introductory text concerned with the processes that create certain hazards and disasters whilst explaining the actions needed to alleviate the most serious consequences of such phenomena. At the outset, it was realized that an account restricted to rapid-onset natural hazards and disasters was insufficient. From the First Edition, technological hazards were included and, as the scope of hazards has spread, so other material has claimed its rightful place. Consistent attempts have been made to position the book within the broad stream of contemporary theory and practice. But, largely because of the current pace and significance of both hazards research and global environmental change, an update of the existing package was no longer adequate. Environmental hazards have emerged as more than site-specific, or community-specific, threats from a local source, whatever the nature of that source. They have now to be placed more explicitly within a framework of global-scale processes, both physical and human, whilst resisting any temptation to widen the scope of enquiry beyond the underlying ‘environmental’ remit and so create a truly unmanageable task for author and reader.
1.2 STATEMENT OF THE PROBLEM
Human-made hazards while not immediately health-threatening may turn out detrimental to man’s well-being eventually, because deterioration in the environment can produce secondary, unwanted negative effects on the human ecosphere. The effects of water pollution may not be immediately visible because of a sewage system that helps drain off toxic substances. If those substances turn out to be persistent (e.g. persistent organic pollutant), however, they will literally be fed back to their producers via the food chain. In that respect, a considerable number of environmental hazards listed below are man-made (anthropogenic) hazards.