Pollution control

Pollution control is a term used in environmental management. It means the control of emissions and effluents into air, water or soil. Without pollution control, the waste products from consumption, heating, agriculture, mining, manufacturing, transportation and other human activities, whether they accumulate or disperse, will degrade the environment. In the hierarchy of controls, pollution prevention and waste minimization are more desirable than pollution control.

Major forms of pollution and major polluted areas

The major forms of pollution are listed below along with the particular pollutants relevant to each of them:

Air pollution, the release of chemicals and particulates into the atmosphere. Common gaseous air pollutants include carbon monoxide, sulfur dioxide, chlorofluorocarbons (CFCs) and nitrogen oxides produced by industry and motor vehicles. Photochemical ozone and smog are created as nitrogen oxides and hydrocarbons react to sunlight. Particulate matter, or fine dust is characterized by their micron size PM 10 to PM2.5.

Water pollution, by the release of waste products and contaminants into surface runoff into river drainage systems, leaching into groundwater, liquid spills, wastewater discharges, eutrophication and littering.

Soil contamination occurs when chemicals are released by spill or underground leakage. Among the most significant soil contaminants are hydrocarbons, heavy metals, MTBE, herbicides, pesticides and chlorinated hydrocarbons.

Radioactive contamination, resulting from 20th century activities in atomic physics, such as nuclear power generation and nuclear weapons research, manufacture and deployment. (See alpha emitters and actinides in the environment.)

Noise pollution, which encompasses roadway noise, aircraft noise, industrial noise as well as high-intensity sonar.

Light pollution, includes light trespass, over-illumination and astronomical interference.

Visual pollution, which can refer to the presence of overhead power lines, motorway billboards, scarred landforms (as from strip mining), open storage of trash or municipal solid waste.

• Thermal pollution, is a temperature change in natural water bodies caused by human influence, such as use of water as coolant in a power plant.

Protect yourself from foodborne illness

People tend to associate food poisoning with restaurants, and given the headlines over the past few weeks it's easy to see why. In mid-December dozens of confirmed cases of E.coli 0157:H7 infection in several states were linked to the fast-food chain Taco Bell. And the outbreak came just weeks after smoothie giant Jamba Juice announced that drinks containing strawberries sold at its stores in Arizona, southern Nevada, and Southern California may have been contaminated with the bug Listeria monocytogenes.

However, you don't need to go much farther than your own kitchen to contract a foodborne illness; most cases of food poisoning occur at home. Below are a few pointers to help you protect yourself and your family:

Foods that appear fresh aren't necessarily safe. That's because the microorganisms that cause food poisoning are different from those that cause spoilage. Assume that all raw meat, fish, and eggs are contaminated, and handle them carefully. When shopping, place meat in separate plastic bags (and store it that way in the refrigerator) to keep its juices away from other foods. And minimize bacterial growth by keeping temperatures down: Choose cold foods last and bag them together; if they'll be unrefrigerated longer than an hour, pack them in a cooler.

Freezing kills only some of the bacteria. If food defrosts at a warm temperature, the surviving organisms resume multiplying even faster than before. That's because freezing breaks down the cell walls, giving bacteria easier access to the nutrients-and it's the strongest organisms that survive. So thaw foods in the refrigerator, not on the counter. Or defrost them in a microwave or in a watertight plastic bag submerged in cold water; food thawed in those ways should be cooked immediately. In addition, don't refreeze foods that have thawed, and don't buy foods that may have been refrozen; signs of refreezing include crystals on the container and clumping of the foods inside.

Rinsing raw meat is more likely to contaminate the kitchen than decontaminate the food. However, if rinsing is needed to remove bits of packaging, do it carefully. Try to handle raw food in just one part of the kitchen—say, on a cutting board used only for such food. Mop up spilled juices with paper towels. Then wash with hot soapy water any faucets, sink handles, counters, and utensils that you touched while handling the food. (And wash your hands, too.) Don't put cooked meat back on the same plate that held it raw, and boil leftover marinade for a full minute if you wish to use it as a sauce for cooked food.

Food Poisoning Symptoms

Symptoms of food poisoning depend on the type of contaminant and the amount eaten. The symptoms can develop rapidly, within 30 minutes, or slowly, worsening over days to weeks. Most of the common contaminants cause nausea, vomiting, diarrhea, and abdominal cramping. Usually food poisoning is not serious, and the illness runs its course in 24-48 hours.