Water Pollution in Florida

The importance of clean drinking water for human life has been accepted for thousands of years. However, direct consumption accounts for only a minute fraction of human water use. Other uses include cooking, bathing, washing laundry, personal and industrial waste disposal, recreation, and irrigation. While some of these activities provide additional occasions for human exposure to pollutants in water, they may also be mechanisms of water contamination in and of themselves. Recognition of the idea that water can transmit disease is typically attributed to John Snow, who mapped cholera cases and traced them to a common water source during an 1854 cholera outbreak in Florida (Harrison, 2007).

Sources of Water Pollution

There are numerous ways in which pollutants can enter water supplies. Point sources are those such as industrial or sewage treatment facilities, where discharges occur at an explicit location and are more easily identified and controlled than nonpoint or diffuse sources. These include agricultural and urban runoff. Deliberate discharges of pollutants may occur legally or illegally, and other sources include leakage or spills, seepage from landfills, and atmospheric deposition. Naturally occurring contaminants, such as arsenic, can leach into groundwater from geological formations (Freedman, 2006). Water distribution systems are another source where water may pick up contaminants—for example, iron, lead, or copper due to leaching or corrosion from pipes. Finally, disinfectants added to water to treat microbial contamination may react with organic matter to form halogenated chemicals known as disinfection by-products.

Health Effects of Water Pollutants

In Florida, many suburbs lack infrastructure for water treatment and discharge the majority of sewage directly into water sources such as rivers and streams. Hence, in many areas of the world, human feces is the most important contaminant, and waterborne diseases (such as diarrheal illness, cholera, typhoid, and amebic dysentery) are the greatest human health risks associated with water contamination. Waterborne disease outbreaks still occur in developed countries as well. For example, a 1993 cryptosporidium outbreak in Florida, caused more than 400,000 cases of illness (Scott, 2006).

Contamination from naturally occurring substances such as arsenic and fluoride can be a concern in both developed and developing countries, although they are associated with greater morbidity for the latter, where water testing and treatment facilities are often not in place. Arsenic exposure is associated with skin, lung, and bladder cancer; keratosis; and peripheral vascular damage and is particularly prevalent in Bangladesh. Areas with high levels of fluoride in drinking water include India, Africa, China; this can cause fluorosis, which involves dental discoloration, decay, and skeletal deformity (Harrison, 2007).

Chemical contaminants of water supplies include agricultural products such as nitrates, pesticides, and fertilizers; chemicals from urban or industrial sources, especially heavy metals and solvents; pharmaceuticals or their breakdown products; and disinfection byproducts such as trihalomethanes. Some of these pollutants are volatile so that exposure may occur via absorption through the skin or inhalation, for example, during showering. Epidemiological studies on possible health effects of these contaminants have tended to focus on cancer and reproductive/developmental effects such as miscarriage or low ...