In a way, the story of pollution started with the story of the progress of civilisation. Soot in the cave ceiling where early man got a fire going to warm himself or to cook his food, discovery of iron, smelting it, forging of different metals—each step that has taken early human civilisation forward by several steps are also events that introduced contaminants into the natural environment - all accompanied with undesirable changes. No doubt, the industrial revolution and the burning of fossil fuels to meet man’s energy requirements spurred environmental pollution to levels never imagined before. The impact of pollution on human health can never be understated and can cause a range of symptoms and diseases including respiratory and cardiovascular diseases. Pollution can assume different forms involving chemicals or energy sources like sound, heat or even light and can take place anywhere - air, water or earth. Air pollution sources are power or heat generating processes, burning of solid wastes, industrial processes, and transportation. Water is polluted by the introduction of chemical, physical, or biological material mainly by industrial effluents, mining and agricultural wastes, sewage and domestic wastes. Land is polluted by poor agricultural practices, mineral exploitation, industrial waste dumping, and indiscriminate disposal of urban wastes. Each pollutant, as the graph shows below, has an adverse impact on human health.
The presence of particulate matter (PM) in air causes cancer and cardiovascular conditions and lung diseases. A PM is actually a very fine solid or liquid particle that lies suspended in a gas. Its origin can be natural or due to human activity. Human activity like burning of fossil fuels in vehicles and other modes of transportation, factories, power plants and various industrial processes generate huge amounts of aerosols. In 2010 alone, the PM caused 1.3 million deaths in East Asia and 0.7 million in South Asia. Like PM, the indoor air pollution causes number of diseases. Responsible for nearly 3% of the global burden of disease, household air pollution have caused 1.1 million deaths in East Asia in 2010 and 1.3 million in South Asia in the same year. Another dangerous pollution - lead pollution - is caused mainly due to operating lead smelters, metal processing plants, incinerators and using chemical paints. Besides fatal effects on human beings and animals, when high amounts are absorbed, lead can cause birth defects in unborn children. In 2010, exposure to lead pollution have caused 0.2 million deaths each in East Asia and South Asia.
Increasing urbanisation and population ageing (leading to more susceptible people) are likely to outstrip the benefits of any emission reductions. China and India, two big countries, remain vulnerable to the premature deaths linked to ground-level ozone. By the year 2050, these countries will face the worse fallout of the ozone pollution in the region. According to the 2010 WHO report, among Asian countries, India led the death tally due to environmental factors with 2.6 million, edging out China with 2.3 million, followed by Indonesia, Bangladesh and Pakistan. The indoor and outdoor air pollution, unsafe water conditions, lead exposure and injuries contribute significantly to the burden of disease among children. Many of the environmental factors-related deaths are estimated to occur in East Asia and South Asia, where population is high and air pollution is severe. Air pollution in South Asia, for example, has been ranked the sixth most dangerous killer, just below blood pressure, tobacco smoking, indoor air pollution, poor intake of fruits, and diabetes. Studies also show that if the figures for outdoor air pollution are combined with those of indoor air pollution, caused largely by people cooking indoors with wood or coal, polluted air would now rank as the second highest killer in the world, behind blood pressure. Overall Asia, as the graph shows, faces the brunt of pollution as it is contributing to diseases and premature deaths.
In the year 2011, an astounding 768 million people worldwide relied on unsafe drinking water sources. The same year, one billion people still defecated in the open with 90% of all open defecation taking place in rural areas. While 2.5 billion people lacked access to an improved sanitation facility, 693 million used facilities that did not meet minimum standards of hygiene. Not surprisingly, till 2004, 1.9 million people died worldwide every year just only from diarrhea, accounting for 4.2% of the global burden of disease. And about 88% of diarrheal deaths in the world are caused by unsafe water, sanitation or hygiene (WSH). Besides diarrhea, unavailability and lack of access to safe drinking water, proper sanitation and hygiene is a leading cause of various diseases and conditions like malnutrition, intestinal nematode infections, lymphatic filariasis, trachoma, schistosomiasis, malaria and other infectious diseases. Although certain progress is noticeable in the global fight for safe water, sanitation and hygiene (WSH) - now one child dies every 21 seconds due to a water-related disease, as against one in 15 seconds in 2009 - a joint WHO-UNICEF report says some 2.4 billion people, or one-third of the world’s population, will remain without access to improved sanitation in 2015. In Asia, according to the 2010 WHO report, India led the number of deaths (454,367) due to unsafe water, followed by Bangladesh (64,970), Pakistan (59,188), China (54,922) and Indonesia (31,675).