PUBLIC HEALTH PROGRAMS

Sanitation and Pollution Control
Disease-causing organisms are often transmitted through contaminated drinking water. The single most effective way to limit water-borne diseases is to ensure that drinking water is clean and not contaminated by sewage.

In many parts of the world, public health officials establish sewage disposal and solid waste disposal systems, and regularly test water supplies to ensure they are safe. These systems are expensive to develop and maintain, however, and many developing nations have poor or insufficient water sanitation systems.

The United Nations estimates that between 5 and 10 million people die each year from water-borne diseases such as cholera.

Photo Researchers, Inc./Sinclair Stammers Many diseases, such as hepatitis A and those caused by the Salmonella bacteria, are transmitted through food. When food is not washed or thoroughly cooked, or when food is stored at temperatures that are hospitable to disease-causing organisms, people who eat the food are subject to infection.

Public health programs establish and enforce laws for safe food storage and preparation. For example, in most nations food-processing plants, restaurants, and grocery stores are legally required to follow strict food-safety guidelines established by public health officials.

Phototake NYC/Jan Callagan Public health officials also establish and oversee programs to control flies, rats, and other animals that spread disease-causing microbes.

For example, pesticide programs in parts of Africa significantly reduced rates of trypanosomiasis, a sometimes fatal disease commonly known as sleeping sickness that is transmitted by the African tsetse fly. Several often deadly diseases are transmitted by rodents.

Hantaviruses transmitted by mice, for example, can cause a deadly type of severe respiratory disease. Humans are infected when they inhale dust containing virus-infected rodent feces. By preventing rodents from living in or near human dwellings, public health officials seek to reduce rates of these types of infections.

Environmental pollution is another preventable cause of disease and disability, and in most countries public health officials address the adverse health effects of air pollution and water pollution.

Public health officials may work in conjunction with pollution control organizations to establish and enforce pollution limits and advise the general population when pollution levels exceed safe limits.

For example, when air pollution reaches harmful levels in Los Angeles, California, public health and environmental officials warn the public of the potential dangers. When chemical contamination renders ponds or lakes unsafe for swimming, health officials post warning signs informing the public of the hazard.

They may close down businesses that consistently put harmful pollutants into the environment, or prohibit distribution and sale of food harvested from contaminated regions.