Risk Wise

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Respiratory health

Combustion of fossil fuel and biomass is the dominant

source for energy worldwide, driving national economies

and development. The combustion of these fuels results

in the emission of gaseous species like carbon dioxide,

carbon monoxide, oxides of nitrogen, sulphur dioxide

and hydrocarbons, besides suspended particulate matter.

It is well established that exposure to these pollutants

can have a range of adverse health effects, especially if

serious pollution episodes occur. Air pollution, both

outdoor and indoor poses a great risk to human health.

The impacts of ozone levels and benzene emissions,

which have not been studied sufficiently in most of the

developing countries where ambient concentrations of

these species are generally increasing, would probably

add more to the total loss in national productivity due

to increased morbidity.

Extensive studies correlating indoor pollution and its

impacts such as acute respiratory infections, chronic

obstructive pulmonary diseases (e.g. chronic bronchi-

tis), lung cancer, tuberculosis and prenatal effects are

well documented. Long-term exposure to low levels of

pollution may result in or aggravate chronic bronchitis,

pulmonary emphysema, bronchial asthma, chronic

cough, lung cancer and decreased resistance to infec-

tions. Excessive secretion of bronchial mucous is the

hallmark of chronic air pollution effects. Dust allergens

including pollen of size 1-90 μm in diameter can induce

or trigger allergic reactions in susceptible people.

In view of the adverse effects of air pollution, some

studies have been carried out in South Asian countries

which provided inputs for evolving technologies, policies,

laws and regulatory mechanisms to control the problem of

poor air quality. While the developed countries have been

able to improve their ambient air quality significantly, the

developing countries are still facing a major challenge in

tackling this problem in spite of several measures taken

so far. This is because economic development and associ-

ated lifestyle changes in the region are resulting in an

increasing rate of air pollutant emissions, which might

need additional policy measures to prevent human health

risks and boost overall national productivity.

an occupational hazard for both outdoor and indoor workers. This

could lead to death or chronic ill health from the after-effects of heat-

stroke.

Large areas in the South Asian region that experience high

temperatures for a significant time in the summer seasons are highly

vulnerable to heat stress, which affects poor people more as evidenced

by the occurrence of heatstroke in metal workers in Bangladesh

and

rickshaw pullers in South Asia.

In India, mortality due to heat waves

shows an increasing trend. For example, in 1981 there were seven

heat wave days with 63 deaths, which rose to 27 events and 1,658

deaths in 1998 and 70 events with 1,539 deaths in 2003.

Clearly,

this shows the need for appropriate intervention such as augment-

ing forecasting measures, creating shelters and gearing up health care

facilities to cope with this kind of human health risk.

Malaria

Malaria is a public health problem in 90 countries in the world, cover-

ing 40 per cent of the human population. South Asia is especially

vulnerable to malaria risks. About 1.8 million malaria cases have been

reported causing about 1,000 deaths annually in India. It is highly

prevalent in the forest areas and tribal belts of the South Asian region.

Malaria is one of the vector-borne diseases that is affected by a large

number of factors related to human population, the parasite, vector

bionomics and the environment; including temperature, precipitation,

humidity and wind conditions of a region, which also have a role in

determining transmission dynamics of the area. Additionally, it is

expected to be most sensitive to long-term climate and environment

change. Malaria has been on the increase due to a growth in urban-

ization and the migration of people searching for a better livelihood.

For example, only sporadic cases of malaria were reported from states

in north-east India before 1980. However, a widespread malaria

outbreak occurred in Assam in 1995 and many deaths were reported

from several primary health centres in the region. This increase in

endemicity was traced to a large-scale migration of labour to the forests

of Assam from areas with a higher prevalence of the disease.

Malaria is mostly endemic in the South and Southeast Asian coun-

tries. Attempts to eradicate malaria globally have been seriously

hampered due to the fact that malaria vectors have become more resis-

tant to insecticides, and the parasites that cause the disease have also

become resistant to chloroquine and possibly other anti-malarial drugs.

This is making prevention and treatment increasingly difficult and costly.

India has also spent a considerable amount of money on malaria

control operations through its National Malaria Eradication

Programme (NMEP), but due to the increasing resistance of mosqui-

toes to pesticides and of parasites to anti-malarial drugs, the

effectiveness of malaria control attempts could not be fully success-

ful. Therefore there is a need to develop new region-specific coping

strategies to reduce human health vulnerability to malaria. For

example, during 2000-2001 under the Roll Back Malaria initiative of

the World Health Organization, a malaria situation analysis was

undertaken in the West Aizawl district of Mizoram in India. This

revealed that although there were negligible vacant positions in the

anti-malaria department, an availability of 100 per cent of the required

financial assistance from the Government of India, a vector fully

susceptible to Dichloro-Diphenyl-Trichloroethane (DDT), coverage of

indoor residual spray to the tune of 85 per cent and a more than 95

per cent literacy rate, there were still deaths due to malaria. This indi-

cates that the intervention measures were inadequate in handling the

situation, thus warranting investigation and development of region-

specific intervention measures.

Use of a ceramic water filter in an Indian kitchen

Image: C. Sharma