Developed countries have shifted ‘burden’ to developing ones
Environmental pollution has many facets, and the resultant health risks include diseases in almost all organ systems. Each pollutant has its own health risk profile, which makes summarizing all relevant information difficult. Nevertheless, public health practitioners and decision makers in developing countries need to be aware of the potential health risks caused by air pollution. Here we will focus on the problems caused by air at the community, country, and global levels.
Nature, Causes, and Burden of Air Pollution
Air pollutants are usually classified into suspended particulate matter (PM) (dusts, fumes, mists, and smokes); gaseous pollutants (gases and vapors); and odors. Suspended PM can be categorized according to total suspended particles: the finer fraction, PM10, which can reach the alveoli, and the most hazardous, PM2.5 (median aerodynamic diameters of less than 10.0 microns and 2.5 microns, respectively). Much of the secondary pollutants PM2.5 consists of created by the condensation of gaseous pollutants—for example, sulfur dioxide (SO2) and nitrogen dioxide (NO2). Types of suspended PM include diesel exhaust particles; coal fly ash; wood smoke; mineral dusts, such as coal, asbestos, limestone, and cement; metal dusts and fumes; acid mists (for example, sulfuric acid); and pesticide mists. Gaseous pollutants include sulfur compounds such as SO2 and sulfur trioxide; carbon monoxide; nitrogen compounds such as nitric oxide, NO2, and ammonia; organic compounds such as hydrocarbons; volatile organic compounds; polycyclic aromatic hydrocarbons and halogen derivatives such as aldehydes; and odorous substances. Volatile organic compounds are released from burning fuel (gasoline, oil, coal, wood, charcoal, natural gas, and so on); solvents; paints; glues; and other products commonly used at work or at home. Volatile organic compounds include such chemicals as benzene, toluene, methylene chloride, and methyl chloroform. Emissions of nitrogen oxides and hydrocarbons react with sunlight to eventually form another secondary pollutant, ozone, at ground level. Ozone at this level creates health concerns, unlike ozone in the upper atmosphere, which occurs naturally and protects life by filtering out ultraviolet radiation from the sun.
Sources of Outdoor Air Pollution
Outdoor air pollution is caused mainly by the combustion of petroleum products or coal by motor vehicles, industry, and power stations. In some countries, the combustion of wood or agricultural waste is another major source. Pollution can also originate from industrial processes that involve dust formation (for example, from cement factories and metal smelters) or gas releases (for instance, from chemicals production). Indoor sources also contribute to outdoor air pollution, and in heavily populated areas, the contribution from indoor sources can create extremely high levels of outdoor air pollution. Motor vehicles emit PM, nitric oxide and NO2 (together referred to as NOx), carbon monoxide, organic compounds, and lead. Lead is a gasoline additive that has been phased out in industrial countries, but some developing countries still use leaded gasoline. Mandating the use of lead-free gasoline is an important intervention in relation to health. It eliminates vehicle-related lead pollution and permits the use of catalytic converters, which reduce emissions of other pollutants. Another type of air pollution that can have disastrous consequences is radioactive pollution from a malfunctioning nuclear power station, as occurred in Chernobyl in 1986. Radioactive isotopes emitted from the burning reactor spread over large areas of what are now the countries of Belarus, the Russian Federation, and Ukraine, causing thousands of cases of thyroid cancer in children and threatening to cause many cancer cases in later decades.
Exposure to Air Pollutants
The extent of the health effects of air pollution depends on actual exposure. Total daily exposure is determined by people’s time and activity patterns, and it combines indoor and outdoor exposures. Young children and elderly people may travel less during the day than working adults, and their exposure may therefore be closely correlated with air pollution levels in their homes. Children are particularly vulnerable to environmental toxicants because of their possibly greater relative exposure and the effects on their growth and physiological development. Meteorological factors, such as wind speed and direction, are usually the strongest determinants of variations in air pollution, along with topography and temperature inversions. Therefore, weather reports can be a guide to likely air pollution levels on a specific day. Workplace air is another important source of air pollution exposure. Resource extraction and processing industries, which are common in developing countries, emit dust or hazardous fumes at the worksite. Such industries include coalmining, mineral mining, quarrying, and cement production. Developed countries have shifted much of their hazardous production to developing countries. This shift creates jobs in the developing countries, but at the price of exposure to air pollution resulting from outdated technology. In addition, specific hazardous compounds, such as asbestos, have been banned in developed countries, but their use may still be common in developing countries.
Impacts on Health
Epidemiological analysis is needed to quantify the health impact in an exposed population. The major pollutants emitted by combustion have all been associated with increased respiratory and cardiovascular morbidity and mortality. The most famous disease outbreak of this type occurred in London in 1952 (U.K. Ministry of Health 1954), when 4,000 people died prematurely in a single week because of severe air pollution, followed by another 8,000 deaths during the next few months. In the 1970s and 1980s, new statistical methods and improved computer technology allowed investigators to study mortality increases at much lower concentrations of pollutants. A key question is the extent to which life has been shortened. Early loss of life in elderly people, who would have died soon regardless of the air pollution, has been labeled mortality displacement, because it contributes little to the overall burden of disease. Long-term studies have documented the increased cardiovascular and respiratory mortality associated with exposure to PM. Another approach is ecological studies of small areas based on census data, air pollution information, and health events data, with adjustments for potential confounding factors, including socioeconomic status. Such studies indicate that the mortality increase for every 10 micrograms per cubic meter (μg per m3) of PM2.5 ranges from 4 to 8 percent for cities in developed countries where average annual PM2.5 levels are 10 to 30 μg/m3. Many urban areas of developing countries have similar or greater levels of air pollution. The major urban air pollutants can also give rise to significant respiratory morbidity. Other effects of ambient air pollution are post neonatal mortality and mortality caused by acute respiratory infections, as well as effects on children's lung function, cardiovascular and respiratory hospital admissions in the elderly, and markers for functional damage of the heart muscle. Asthma is another disease that researchers have linked to urban air pollution. Leaded gasoline creates high lead exposure conditions in urban areas, with a risk for lead poisoning, primarily in young children. The main concern is effects on the brain from low-level exposure leading to behavioral aberrations and reduced or delayed development of intellectual or motoric ability. Urban air pollution and lead exposure are two of the environmental hazards that WHO assessed as part of its burden-of-disease calculations for the World Health Report. The report estimates that pollution by urban PM causes as much as 5 percent of the global cases of lung cancer, 2 percent of deaths from cardiovascular and respiratory conditions, and 1 percent of respiratory infections, adding up to 7.9 million disability-adjusted life years based on mortality only. This burden of disease occurs primarily in developing countries, with China and India contributing the most to the global burden. Eastern Europe also has major air pollution problems, and in some countries, air pollution accounts for 0.6 to 1.4 percent of the total disability-adjusted life years from mortality. WHO concludes that 0.4 percent of deaths and 0.9 percent (12.9 million) of all disability-adjusted life years may be due to lead exposure.
White Revolution of India
India had been an importer of dairy products but the White Revolution turned it into one of the largest producers. TreeTake recalls the ‘operation’ that ‘flooded’ the country with milk & milk products... India produces around 17% milk of the world. About 80% of the milk production in the country is in the organized sector while the remaining 20% is shared equally by the cooperatives and private diaries. India has low Milk productivity as compared to western countries; still it tops the list of milk producing country in the world because of the larger number of cattle in the country. It produced 146.31 million tonnes of milk in 2014-15 and 155.5 MT in 2015-16. Uttar Pradesh, Rajasthan, Andhra Pradesh, Punjab and Haryana are the major milk producing states in India. India is also the largest producer of buffalo milk in the world. Dr Verghese Kurien is called the father of the White Revolution in India. Operation Flood was a rural development programme started by India's National Dairy Development Board (NDDB) in 1970. One of the largest of its kind, the programme objective was to create a nationwide milk grid. It resulted in making India one of the largest producers of milk and milk products, and hence is also called the White Revolution of India. It also helped reduce malpractices by milk traders and merchants. Varghese Kurien (chairman of NDDB at that time), then 33, gave the professional management skills and necessary thrust to the cooperative, and is considered the architect of India's White Revolution (Operation Flood). The bedrock of Operation Flood has been village milk producers' cooperatives, which procure milk and provide inputs and services, making modern management and technology available to members. Operation Flood's objectives included: Increase milk production ("a flood of milk"); Augment rural incomes; Fair prices for consumers. Operation Flood was jointly sponsored by the European Economic Community, the World Bank, and India's National Dairy Development Board. The UNDP provided technical assistance by sending foreign experts, consultants, and equipment to India. The World Bank and its affiliates supported agricultural extension, social (community-based) forestry, agricultural credit, dairy development, horticulture, seed development, rain-fed fish farms, storage, marketing, and irrigation. Operation Flood was implemented in three phases: Phase I: (1970–1980) Phase I was financed by the sale of skimmed milk powder and butter oil gifted by the European Union (then the European Economic Community) through the World Food Programme. NDDB planned the programme and negotiated the details of EEC assistance. During its first phase, Operation Flood linked 18 of India’s premier milksheds with consumers in India’s major metropolitan cities: Delhi, Mumbai, Kolkata and Chennai, thus establishing mother dairies in four metros. Phase II: (1981–1985) increased the milk-sheds from 18 to 136; 290 urban markets expanded the outlets for milk. By the end of 1985, a self-sustaining system of 43,000 village cooperatives with 4.25 million milk producers were covered. Domestic milk powder production increased from 22,000 tons in the pre-project year to 140,000 tons by 1989, all of the increase coming from dairies set up under Operation Flood. In this way EEC gifts and World Bank loan helped promote self-reliance and direct marketing of milk by producers' cooperatives increased by several million litres a day. Phase III: (1985–1996) enabled dairy cooperatives to expand and strengthen the infrastructure required to procure and market increasing volumes of milk. Veterinary first-aid health care services, feed and artificial insemination services for cooperative members were extended, along with intensified member education. This phase consolidated India's dairy cooperative movement, adding 30,000 new dairy cooperatives to the 42,000 existing societies organized during Phase II. Milk-sheds peaked to 173 in 1988-89 with the numbers of women members and Women's Dairy Cooperative Societies increasing significantly. The Women's Dairy Cooperative Leadership Programme (WDCLP) was launched in 1995 as a pilot programme with the objective of strengthening the dairy cooperative movement by significantly increasing women's participation as active members and as leaders in the governance of cooperative societies, unions and federations. NDDB provided assistance to milk producers' cooperative unions in conducting several activities to achieve WDCLP objectives. The WDCLP encouraged cooperative milk producers' unions to identify women staff to participate in training designed to develop their latent potential. In the village, a key strategy was training and positioning a local woman as a resource person to encourage and support women involvement in their dairy cooperative. Phase III gave increased emphasis to research and development in animal health and animal nutrition. Innovations like vaccine for Theileriosis, bypassing protein feed and urea-molasses mineral blocks, all contributed to the enhanced productivity of milch animals. By September 1996, about 73,300 dairy cooperative societies had been organised in 170 milk sheds involving over 9.4 million farmer members. Far reaching consequences: The year 1995-96 marked the termination of Operation Flood III, funded by a World Bank loan, EEC food aid and internal resources of NDDB. At the conclusion of Operation Flood III, 72,744 DCSs in 170 milk-sheds of the country, having a total membership of 93.14 lakh had been organized. The targets set had either been effectively achieved or exceeded. However, procurement targets could not be reached as private agencies started procuring milk from the cooperative villages, following the new delicensing policy under the Government's program of economic liberalization. The conditions for long-term growth in procurement had been created. An assured market and remunerative producer prices for raw milk, technical input services including AI, balanced cattle feed and emergency veterinary health services had all contributed to sustained increases in milk production. Three state-of-the-art dairies designed to produce quality products for both the domestic and export markets had been commissioned. While the demand for milk was rising under Operation Flood, the total cattle population remained more or less static. If milk production had to be increased, the buffalo and milk breeds of cattle had to be upgraded. Non-descript cows had to be crossbred with exotic semen to increase their milk production to make them more efficient converters of feed. With this objective in mind, thrust was given to intensive research and development in animal husbandry. Today, animal breeding is an integration of three major areas, artificial insemination and quantitative genetic techniques, embryo transfer and embryo micro manipulation techniques and biotechnology and genetics engineering. The optimal genetic improvement can be achieved by making use of developments in each of these areas. Features responsible for the success of 'Operation Flood' in India: Adoption of new methods in the case of cattle in animal husbandry Changing the composition of feed ingredients in different proportions Cost reduction and technology management Modernization of process and plant technology Interventions for productivity increase Frontier technologies like DNA vaccines and genetically engineered bovine somatotropin, embryo transfer technology and in vitro fertilization of oocytes Outstanding Results: The milk production in India increased from 17 MT in 1950- 51 to about 155.5 MT in 2015-16.