It is now well established that air pollution leads to considerable levels of mortality and morbidity. Global research and well as the little research that exists in India reveals a frightening picture of deadly air. Scientists are finding that fine particulate matter, or respirable particulate matter (RSPM) - less than 10 micron - in the air are particularly dangerous. A recent study - done over 16 years, involving over 500,000 people --published in Journal of American Medical Association (JAMA) reveals that fine particles related pollution leads to lung cancer, and cardiopulmonary mortality. With an increase in each 10 microgrammes per cubic metre of fine particles the risk of lung cancer increased by 8 per cent. (Source: Arden pope et al 2002, Lung cancer, cardiopulmonary mortality, and long term exposure to fine particulate air pollution, Journal of American Association 2002; 287:1132-1141). (Annexure 1).

A. Some facts on air pollution and public health in India

Premature Death
In a study conducted by Harvard University, for a period of 14-16 years and published in 1993, researchers followed the health of more than 80,000 people in six small cities that fell along a gradient of air pollution concentrations.
Results:
a)    As particle concentrations increased, there was an almost directly proportional increase in the death rate in the residents studied.
b)    Residents of the most polluted city in the study, Steubenville, Ohio, had a 26per cent increased risk of premature mortality, compared to the residents of the cleanest city studied, Portage, Wisconsin.
Source: New England Journal of Medicine, Volume; 343, 1993

Increased Hospitalisation
This study, conducted by scientists of the John Hopkins University in 90 largest US cities, found strong evidence linking daily increases in particulate pollution to increases in death.
Results:
a)    Strong and consistent associations between daily particulate air pollution levels and hospital admissions among the elderly particularly from heart- and lung-related diseases.
b)    For each 10 microgram per cubic metre increase in PM10, there was 1.0 per cent increase in hospital admissions for cardiovascular disease and 2 per cent increase in admissions for pneumonia and chronic obstructive pulmonary disease.
Source: Health Effects Institute Research Report 94, 2000

Increase In Daily Mortality
In a study published in 2000, investigators from Harvard Medical School used data on the elemental composition of size-fractioned particles to identify the sources of fine particulates in six eastern U.S. cities that were subjected to long-term pollution study. Each of these fractions was examined in association with daily mortality rates in each city.
Results:
a)    The study reported that a 10 microgram per cubic metre increase in PM 2.5 from mobile sources accou8nted for a 3.4 per cent increase in daily mortality, while the equivalent increase in fine particles from coal combustion sources accounted for a 1.1 per cent increase.
Source: Environmental Health Perspectives 108:941-947, October 2000.

Particulate Pollution Advances Death by Months
Researchers from John Hopkins University and Harvard Medical School have done a study, which shows that air pollution advances death in people already critically ill.
Results:
a)    For chronic obstructive pulmonary disease and ischemic heart disease, most of the deaths seem to be advanced by a few months on average.
b)    Effect estimates increased when examining longer time periods, suggesting that cumulative exposure are more harmful than daily exposure.
Source: American Journal of Epidemiology 2000, Vol: 151.

People With Cardiac Or Respiratory Diseases are more Vulnerable
Scientists from the McGill University of Montreal, Canada, used medical information of people for five years before their death and investigated the link with particulate pollution in a paper published in 2000.
Results:
a)    People with acute lower respiratory disease, congestive heart failure, and a combination of cardiovascular diseases died at higher rates for increases in particulate pollution.
b)    People with cancer, chronic coronary artery disease were found to be more vulnerable to haze and PM 2.5, while effects of sulphate particles were stronger for those with acute and chronic upper respiratory disease.
Source: Health Effects Institute Research Report No: 97, 2000.

Air Pollution Tied to Low Heart Rate Variability, A Risk Factor for Heart Attacks
Three independent studies were conducted in Utah, Baltimore and Boston by the University of North Carolina and Harvard University regarding particulate pollution and risk of heart attacks. In the Utah study researchers measured oxygen saturation and pulse rate in a panel of 90 elderly residents of the Utah valley during winter months, when particulate matter concentration is highest. In the Baltimore and Boston study researchers took 25 minutes of electrocardiogram measurements during different exercise states were taken on a weekly basis.
Results:
a)    In the Utah Valley study researchers found that a small elevation in pulse rate was associated with a rise in PM 10 levels.
b)    Both the Baltimore and Boston studies found out that elevated concentrations of fine particulate matter were associated with lower heart rate variability, and that the association was stronger for people with cardiovascular disease. Low heart rate variability is a marker of poor cardiac control by autonomic nervous system, and is associated with a higher risk of heart attacks and sudden cardiac deaths.
Source: American Journal of Respiratory and Critical Care Medicine, 1999.

Pre-existing Cardiovascular Disease Increases the Risk of PM-related Hospital
Admissions for Respiratory Causes
A ten-year study of Medicare patients in Chicago, reported in 2000, was designed to identify subgroups that are especially susceptible to particulate pollution. Researchers examined records of previous hospital admissions and secondary diagnoses to determine whether people with certain conditions were at a greater risk from air pollution.
Results:
a)    Investigators found that people with asthma had double the risk of a PM10 associated hospital admission, and that people with heart failure had double the risk for PM10-induced COPD admissions.
Source: Environmental Health Perspectives, July, 2000

Growth In Children's Lung Function Is Slowed By Air Pollution
Researchers with the Children's Health Study Led by the University of Southern California monitored levels of major air pollutants in a dozen southern California communities since 1993, while tracking the respiratory health of more than 3,000 school children.
Results:
a)    In fourth-graders, significant deficits in growth of lung function were associated with fine particles, nitrogen dioxide, and inorganic acid vapour.
b)    The deficits were larger for children that spent more time outdoors.
c)    The results suggest that exposure to air pollution may lead to a reduction in maximal attained lung function, which occurs early in adult life, and ultimately to increased risk of chronic respiratory illness in adulthood.
Source: American Journal of Respiratory and Critical Care Medicine, October 2000.

Children's Emergency Room Visits For Asthma Increase on High Air Pollution Days
Scientists from the Atlanta-based Emory University obtained data on emergency department visits for three summers from seven large Atlanta area hospitals. The study published in2000, included information on a variety of pollutants including ozone, a broad range of exposure levels, and a balanced distribution of socio-economic status in the study population.
Results:
a)    Increases in both ozone and particulate matter were found to heighten the risk of pediatric emergency room visits for acute asthma.
Source: American Journal of Epidemiology, Volume: 151, 2000

Ozone Harms Respiratory Health
Researchers from Columbia University and New York University sought to determine whether changes in lung function or respiratory symptoms would occur over the course of a summer among healthy young adults working outdoors in the presence of ozone. The study followed 72 sophomore cadets from the U.S. Military Academy at West Point, New York, during their summer training.
Results:
a)    All the subjects on average experienced a decline in lung function over the course of the summer.
b)    There were also significant increases in reports of cough, chest tightness, and sore throat.
c)    These results suggest an adverse respiratory-health impact of exposures to particulate matter and ozone in healthy young adults engaged in intensive outdoor training.
Source: Archives of Environmental Health, Volume: 55, 2000.

Summertime Haze Exacerbates Asthma In Children
A study by New York University focused on children ages 7 - 13 with moderate to severe asthma who attended a summer "asthma camp" in the early 1990's in the Connecticut River Valley.
Results:
a)    Air pollution, especially ozone, was consistently correlated with acute asthma exacerbations, chest symptoms, and lung function decrements
Source: American Journal of Respiratory and Critical Care Medicine, Volume: 155, 1997

Ozone sends the elderly to the emergency room
A study in Montreal, reported in 1998, examined daily emergency room visits for respiratory illness in 25 hospitals in Montreal, Quebec in relation to summertime air pollution.
Results: though the ozone levels never exceeded the standard of 120 ppb, statistically significant relationships were found between respiratory emergency room visits for patients over age 64, and both 1-hour and 8-hour maximum ozone levels measured the day before.
Source: Environmental Research, Volume 76, 1998

Air pollution and cardiovascular disease
Another study conducted in Valencia, Spain by the Valencia School of Studies for Health during 1994-1996, found that even daily levels of air pollution affected emergency hospital admissions for cardiovascular diseases. A 10 microgramme per cubic metre rise in daily level of sulphur dioxide was found to increase the expected number of cardiovascular admissions by 3 per cent. Nitrogen dioxide was found to be associated with cerebro-vascular admissions.
Source: Journal of Epidemiological and Community Health 1996;50

Air pollution and lung cancer
Researchers of the Loma Linda University, after following a group Seventh-day Adventists form 1977 to 1992, reported in 1999 that men who were exposed to PM10 over 100 micorgramme per cubic metre for 43 days or more per year had a 28 per cent higher risk of dying from any type of non-malignant respiratory disease. The study found in the males, long term exposure to high levels of PM10 was also strongly associated with increased risk of lung cancer death. Men also were at increased risk of lung cancer death if they were exposed long-term to ozone levels exceeding 0.10 part per million (ppm). The current US federal standard is 0.08 ppm averaged over eight hours. The study also found that long-term exposure to sulphur dioxide was strongly associated with lung cancer deaths in both men and women.
Source: American Journal of Respiratory and Critical Care Medicine, February, 1999

Air pollution and asthma
In another study conducted by Chiba University School of Medicine, Japan, for over 3 years on 842 schoolchildren living in seven different communities in Japan, it was found that the incidence of asthma increased among children living in areas with high concentrations of outdoor nitrogen dioxide. A rise of outdoor NO2 concentration by 10 ppb resulted in an increased incidence of wheeze increased incidence of wheeze and asthma but that no such associations were found with indoor NO2 concentration.
Source: International Journal of Epidemiological, Volume 29, 2000

More from environment than from genes
A study that has shocked the western world in based on a survey of cancer incidence amongst 44,7888 pairs of twins in Denmark, Sweden and Finland. The study concludes "Inherited genetic factors make a minor contribution to susceptibility to most type of neoplasm. This finding indicates that the environment (pollution, radiation, diet etc) has the principal role to play in causing sporadic cancer."
Source: New England Journal of Medicine, Volume 343, 2000

Children at risk
According to a study conducted by the Natural Resources Defence Council (NRDC), a US based non-governmental organization the risk of developing cancer is four times higher amongst children travelling in a diesel bus as compared to someone travelling in a car in front of a bus. The study concludes that for every one million children, 23 to 46 children may eventually develop cancer from the excess diesel exhaust they inhale. This means that a child riding a school bus is being exposed to as much as 46 times the cancer risk considered "significant" by the US EPA.
Source: Gina M Solomon et al 2001, No breathing in the aisles: Diesel exhaust inside school buses, Natural Resources Defence Council, USA.

Particulate matter - the killer
1)    Particulate matter has emerged to be the greatest threat to public health among all air pollutants.
2)    According to M G Constantini of Health Effects Institute in Massachusets, USA, penetration and deposition of particulate matter depends on the size of the particle. The smaller the paricle, the greater its ability to penetrate the lungs. The cells of our lungs react first with the components on the surface of the particles. This makes ultrafine particles (smaller than 0.1 micron in size) more dangerous as they have a large surface area and absorb a greater amount of toxic chemicals than the larger particles.
3)    Lidia Morawska of the Centre for Medical and Health Physics at Queensland University of Technology, and Dietrich Schwela of the World Health Organisation in Geneva in their report say that large particles from the bulk of the total mass of particles present in the ambient air. But, when considered in terms of number, ultrafine particles constitute over 80 per cent of particulate matter, although their total mass is usually insignificant in comparison with the mass of the larger particles.


D.    Health effects of air pollution
Health effects of exposure to different air pollutants:

PARTICULATE MATTER:
·    Premature deaths;
·    Reduced lung function;
·    Respiratory and cardiac hospitalisations;
·    Functional limitations as reflected by restricted activity days, and in school children by school absenteeism;
·    Daily prevalence of respiratory disease symptoms; and
·    Infant mortality.

OZONE:
Ozone acts as a respiratory irritant and causes:
a.    Shortness of breath,
b.    Chest pain when inhaling deeply,
c.    Wheezing and coughing;
Long-term, repeated exposure to high levels of ozone may lead to large reductions in lung function, inflammation of the lung lining and increased respiratory discomfort;
Children are more susceptible to ozone pollution;
Excess infant mortality.

LEAD:
·    Lead in air damages the central nervous system, kidneys and the reproductive system;
·    Foetus, infants and children are more vulnerable to lead exposure than adults since lead is more easily absorbed into growing bodies. Also the tissues of small children are more sensitive to the damaging effects of lead. Even at much lower levels of exposure, lead can affect a child's mental and physical growth.


OXIDES OF NITROGEN AND SULPHUR DIOXIDE:

Exacerbate respiratory diseases;
Get converted to nitrate and sulphate particles in the air and contribute particulate pollution.


CARBON MONOXIDE:

Carbon monoxide binds with haemoglobin200-250 times more rapidly than oxygen. Exposure to even low levels of carbon monoxide can lead to oxygen deficiency of tissues, also known as 'tissue hypoxia.' The toxic effects of carbon monoxide first become evident in organs and tissues with high oxygen consumption, such as brain, heart, exercising skeletal muscle and developing foetus.

BENZENE, POLYCYCLIC AROMATIC HYDROCARBONS:

Known human carcinogens