Heavy Metals and Hydrocarbons: Adverse Effects and Mechanism of Toxicity

Chemicals are a part of our daily lives; all living and inanimate matter is composed of many chemicals and every manufactured product involves the use of chemicals. When properly used, these chemicals significantly contribute to the improvement of our quality of life, health, and well-being. When improperly managed, however, certain chemicals are highly hazardous and can negatively affect health as well as the environment. The most important environmental pollutants in areas with high anthropogenic pressure include heavy metals such as cadmium, copper, lead, chromium, and mercury. Their presence in the environment, even in trace amounts, can cause serious problems for all organisms. Though heavy metals are the natural constituents of the Earth's crust, indiscriminate human activities alter their biochemical balance and geochemical cycle. In any mode of entry into the human body, either through inhalation or ingestion, the heavy metals present serious threats to the organism. Prolonged exposure to these toxic metals creates deleterious health effects in humans. Another major group of pollutants includes polyaromatic hydrocarbons, which are formed due to incomplete burning of coal, oil, gas, garbage, or other organic substances and may cause many health hazards in each and every part of the human body. This chapter reviews the toxic effects of many heavy metals and hydrocarbons on human beings as well as the mechanisms of their toxicity. © 2014 Elsevier Inc. All rights reserved.