What are the effects of environmental pollution on human health?

Man's dependence on his immediate environment is immeasurable in many ways. Apart from being his major source of food, he needs it for shelter and raw materials to meet his other numerous needs. The relationship is without doubt mutual as the environment needs man to help check its excess. Its a give and take interaction. A polluted environment lacks the capacity to meet up with its side of the scale. If a major drinking water source of a community or a town becomes polluted the obvious consequence is reduction if not total loss of drinkable water available for consumption by the human population in the area. The same happens when the air within a given area is highly polluted. These two challenges are common within and around urban environments

Overall Health Effects

Many of us experience some kind of air pollution-related symptoms such as watery eyes, coughing, or wheezing. Even for healthy people, polluted air can cause respiratory irritation or breathing difficulties during exercise or outdoor activities. Your actual risk depends on your current health status, the pollutant type and concentration, and the length of your exposure to the polluted air.

People most susceptible to severe health problems from air pollution are:

• Individuals with heart disease - such as coronary artery disease or congestive heart failure

• Individuals with lung disease - such as asthma, emphysema or chronic obstructive pulmonary disease (COPD)

• Pregnant women

• Outdoor workers

• Children under age 14, whose lungs are still developing

• Athletes who exercise vigorously outdoors

High air pollution levels can cause immediate health problems:

• Aggravated cardiovascular and respiratory illness

• Added stress to heart and lungs, which must work harder to supply the body with oxygen

• Damaged cells in the respiratory system

Long-term exposure to polluted air can have permanent health effects:

• Accelerated aging of the lungs

• Loss of lung capacity

• Decreased lung function

• Development of diseases such as asthma, bronchitis, emphysema, and possibly cancer

• Shortened life span

Health Effects from Specific Pollutants

Ground-level Ozone

Ground-level ozone is formed when volatile organic compounds (VOCs) and oxides of nitrogen (NOx) react with the sun's ultraviolet rays. The primary source of VOCs and NOx is mobile sources, including cars, trucks, buses, construction equipment and agricultural equipment.

Ground-level ozone reaches its highest level during the afternoon and early evening hours. High levels occur most often during the summer months. It is a strong irritant that can cause constriction of the airways, forcing the respiratory system to work harder in order to provide oxygen. It can also cause other health problems:

• Aggravated respiratory disease such as emphysema, bronchitis and asthma

• Damage to deep portions of the lungs, even after symptoms such as coughing or a sore throat disappear

• Wheezing, chest pain, dry throat, headache or nausea

• Reduced resistance to infection

• Increased fatigue

• Weakened athletic performance

Particulate Matter (PM)

Particulate Matter is a complex mixture that may contain soot, smoke, metals, nitrates, sulfates, dust, water and tire rubber. It can be directly emitted, as in smoke from a fire, or it can form in the atmosphere from reactions of gases such as nitrogen oxides.

The size of particles is directly linked to their potential for causing health problems. Small particles (known as PM2.5 or fine particulate matter) pose the greatest problems because they can get deep into your lungs and some may even get into your bloodstream. Exposure to such particles can affect both your lungs and your heart.

Scientific studies have linked long-term particle pollution, especially fine particles, with significant health problems including:

• Increased respiratory symptoms, such as irritation of the airways, coughing or difficulty breathing

• Decreased lung function

• Aggravated asthma

• Development of chronic respiratory disease in children

• Development of chronic bronchitis or chronic obstructive lung disease

• Irregular heartbeat

• Nonfatal heart attacks

• Premature death in people with heart or lung disease, including death from lung cancer

Short-term exposure to particles (hours or days) can:

• Aggravate lung disease causing asthma attacks and acute bronchitis

• Increase susceptibility to respiratory infections

• Cause heart attacks and arrhythmias in people with heart disease

Even if you are healthy, you may experience temporary symptoms, such as:

• Irritation of the eyes, nose and throat

• Coughing

• Chest tightness

• Shortness of breath

What is an unprotected water source?

• An unprotected water source refers to streams, rivers, cisterns, and poorly constructed wells, or any well that is not a drilled well and does not have a watertight casing that extends to a depth of at least six meters below ground level. The safety of well water may also be influenced by the original water quality in the watershed or catchment.

• Unprotected water sources can easily become contaminated and unfit for drinking.

What could happen if I drink contaminated water?

• The health effects of drinking contaminated water can range from no physical impact to severe illness or even death.

• Some of the effects of drinking contaminated water can be immediate, or not noticed for many years. These include gastrointestinal and stomach illnesses like:

• nausea

• vomiting

• cramps

• diarrhoea

• Many factors affect the possible impact on health such as:

• the age and general health status of the person

• the type of contaminant

• the amount

• how long the person has been drinking the contaminated water

What could the water be contaminated with?

Private wells can become contaminated with bacteria or chemicals such as nitrates.

• Bacteria - When a water test shows the presence of bacteria, it is considered unsafe to drink until the problem is fixed and the well is disinfected. The absence of bacteria in any one test does not ensure safety at other times. Regular testing throughout the year will establish your well water’s consistency and increase your confidence in its safety. Spring run-off, heavy rain events, or prolonged dry spells as well as wear and tear of the well structures or changes to the water catchment can all potentially affect the quality of your well water.

• Total Coliforms - Total coliform organisms are a group of bacteria that are commonly found in the environment, and are an indicator of the safety of your water. Total coliform bacteria, if present, indicate that disease-causing organisms (bacteria, viruses, parasites) could potentially be present in your water supply.

• E. coli - E. coli bacteria live only in the intestines of animals including humans. If any amount of E. coli bacteria is found in a water sample, it is an indication that human sewage or animal faeces has contaminated the water supply.

• Nitrates - The presence of nitrates in well water is usually the result of farming activities like fertilizing, or seepage from septic systems. If nitrates are at levels above 10 milligrams per litre of water, an infant may suffer from a condition known as “blue baby syndrome” or methaemoglobinaemia. Blue baby syndrome is caused by the nitrates interfering with the blood’s ability to carry oxygen throughout the body.

• Herbicides and Pesticides - Herbicides and pesticides from both agricultural and household use can contaminate wells if used improperly or excessively. Always read and use the amount stated on the manufacturer's label.

Is there a taste, smell, or colour to contaminated water?

Many times the contamination is odourless, colourless, and tasteless.

What should I know about my water system?

1. Know your watershed or catchment. Where does the water come from?

2. Know your source (raw) water quality. How safe is the water that comes straight from your well before it enters any of your plumbing? Does it vary around the year?

3. Only with all these components in place and assessed regularly throughout the year can you have increased confidence in the quality of your drinking water.

4. Know your distribution system. Are piping and plumbing intact everywhere? Are there cross-connections or is there backflow potential? Might plumbing materials add contaminants such as lead to the water?