AN illegal trade in uniodised salt in India is hampering efforts to stamp out
serious iodine deficiency disorders such as goitre and mental retardation,
public health officials are warning.

Over the past five years, most Indian states have introduced laws that
require all salt sold for human consumption to contain a specified level of
iodine. But despite this, small-scale producers are still selling uniodised salt
in India and exporting it to Nepal, Bhutan and the Maldives.

These countries have a high incidence of goitre. A study in the Maldives two
years ago found that a quarter of nearly 3000 children from 200 islands in the
archipelago suffered from the disease. Research published in India earlier this
year by the International Council for Control of Iodine Deficiency Disorders
(ICCIDD) found that some 20 per cent of a group of 1200 Delhi schoolchildren had
goitre. And a 1993 survey, released by the WHO this year, found that in some
Indian states up to 69 per cent of people had the disease.

Several studies show that while 70 per cent of households in India now use
iodised salt, compared to hardly any five years ago, there is still a serious
problem in some of the country’s southern states. According to UNICEF, the UN
children’s agency, fewer than 14 per cent of homes in Tamil Nadu and Karnataka
use iodised salt, compared with 95 per cent in the remote northeast, where
transport of commodities like salt is easier to control.

Chandrakant Pandav, regional coordinator of the ICCIDD, says that in many
areas “there may be iodine but not in the right quantity”. A survey by the
ICCIDD, to be published later this year, found that even in New Delhi—a
major salt trading centre—almost 10 per cent of more than 20 000 samples
brought from home by schoolchildren contained no iodine. Some of those samples
that were iodised contained less than the recommended 15 parts per million of
iodine.

About 13.5 million tonnes of salt are produced in India each year, half of it
for human consumption. But only 4 million tonnes are iodised, according to the
government. This is because most of the country’s 10 000 salt producers are
small-scale, and many of them cannot afford to invest in the equipment needed to
add iodine. Consumers can buy uniodised salt more cheaply than iodised salt, and
this encourages traders to sell salt without iodine, says Sheila Vir, a
nutrition project officer with UNICEF in New Delhi.

A lack of iodine in the diet is the single largest cause of preventable brain
damage and mental retardation in the world, according to the WHO, which is
aiming for universal salt iodisation by 2000. More than 2 million Indians are
afflicted with cretinism because of insufficient iodine intake, according to
estimates by the government’s Salt Department.

Some 57 per cent of the country’s land is affected by degradation, the
independent Tata Energy Research Institute reports in a survey of environmental
damage in India over the 50 years since independence. “The problem hasn’t
received the attention it deserves,” says G. K. Girisha, TERI’s expert on soil
degradation. He says that government policy on land use that was supposed to
reduce erosion and nutrient deficiency by improving farming methods and reducing
tree loss has failed because of a lack of coordination between various
departments.

Estimates of the damage by TERI are considerably higher than those suggested
by other organisations, including the World Bank. Girisha says that this is
because TERI has included the costs of the knock-on effects of soil degradation,
such as increased silting in reservoirs. Even so, he says, the estimates are
probably still too low.

TERI describes erosion as India’s “quiet crisis” and predicts that the
problem will reduce the potential yields of 11 major food crops by 11 to 26 per
cent this year. It warns that the problem is growing worse. The researchers
estimate that the area of critically eroded land has doubled over the past 18
years. Of the 1 per cent of the country’s topsoil that is eroded annually,
two-fifths is permanently lost. The problem is made far worse by deforestation,
they say. Trees, which protect the soil, are regularly cleared for firewood or
to create new farmland.

India’s soil is also being rapidly depleted of nutrients, through intensive
farming. Since 1950, grain production has increased almost fourfold, as more and
more land is farmed, irrigated and fertilised. But in most parts of the country,
the rate of fertiliser use is still relatively low. Each year, crops remove an
estimated 20.2 million tonnes of nitrogen, phosphorus and potassium from the
soil, while fertilisers only add about 5.7 million tonnes of these nutrients. As
demand for food rises with population, the report says, maintaining a soil
nutrient balance will be a major concern. “One of the implications of soil
degradation is concern over food security,” says R. K. Pachauri, director of
TERI.

The growth in farming has been made possible in part by extensive irrigation,
which in turn has raised the water table in many areas and increased salinity.
The area of canal-irrigated farmland doubled between 1950 and 1990, and up to
half of this land is now affected by salinity or alkalinity. The problem mostly
affects the states of Uttar Pradesh, Haryana, Rajasthan, Maharashtra and
Karnataka.

Pachauri says it is not too late to reverse the trend. “If we start now,
maybe we could get something back in 20 years,” he says.

These preliminary findings, announced at a conference in Delhi this week, are part of a programme sponsored by Britain’s Department for International Development, investigating the impacts of pollution on agriculture in developing countries. “There is certainly a major reduction in yields around major cities,” says Nigel Bell of Imperial College in London, who coordinates the programme.

One study, by scientists at the University of the Punjab at Lahore in Pakistan, measured the effects of ozone on soya bean plants at three sites around the city: the botanical gardens in the suburbs, a field 35 kilometres east of the city at Rakh Dera Chahl and a rural area near a busy road 35 kilometres north of the city called Kala Shah Kaku. Ozone levels at all three sites were higher than critical levels for crop damage set by the United Nations Economic Commission for Europe (UNECE).

Last year between mid-August and harvest time in late October, 15 of the 30 experimental plants at each site were treated with ethylene diurea (EDU), which protects plants against ozone. The others were left unprotected. At the botanical gardens, which had the lowest ozone levels, plants that were not protected from ozone yielded 32 per cent less seed by weight than those treated with EDU. At Rakh Dera Chahl the reduction was 49 per cent, and at Kala Shah Kaku 62 per cent.

Ozone levels tend to be high for about 80 kilometres around polluted cities, warns Bell. So crops in regions like Punjab in Pakistan—where large cities lie next to the country’s most productive farms—are particularly at risk.

Researchers in India looking at the effects of sulphur dioxide have found similar damage. A study by researchers at Benares Hindu University found that wheat growing 1.5 kilometres from a power plant in Uttar Pradesh, where sulphur dioxide is almost five times UNECE critical levels, suffered a 49 per cent reduction in yields compared to wheat growing 22 kilometres away.

Crops in developing countries are particularly susceptible to air pollution, says Bell, because a large proportion are irrigated, which causes them to open up pores in their leaves called stomata and so boost their pollution intake. Pollution from industry is also on the increase and there are few pollution controls on cars, numbers of which are growing rapidly.

The first cases of arsenic poisoning in the region were diagnosed 15 years ago in the Indian state of West Bengal, where over 400 villages are now affected (“Death and the devil’s water”, żěè¶ĚĘÓƵ, 16 September 1995, p 14). Large numbers of people in Bangladesh have also developed symptoms, and the government there has started a huge water-testing programme. Bangladesh has turned to Indian experts and international aid organisations for help in dealing with the crisis.

The contaminated water is coming from wells that have been sunk in recent years to replace unhygienic streams and ponds as a source of drinking water. Arsenic leaches into well water from clay, silt and sand, making the problem extremely hard to contain.

People who are poisoned by arsenic develop severe skin problems and a type of gangrene. They often have enlarged livers and go on to develop skin cancer. Doctors in West Bengal say the most severe cases are among poor people who have little protein and vitamins in their diets.

Experts at last month’s conference say the situation in the Ganges delta region is the biggest disaster of its kind in the world. Millions of dollars will be needed for treatment, screening water supplies and finding alternative sources of drinking water. Allan Smith, an epidemiologist at the University of California at Berkeley, who has studied arsenic poisoning in other countries and recently acted as a consultant for the government of Bangladesh, says a health emergency should be called to divert money to the region.

Arsenic poisoning is cumulative. “Each week that exposure continues there is a greater risk that projected long-term diseases like cancer will set in,” says Smith. And D. N. Guha Mazumder of the Institute of Post Graduate Medical Education and Research in Calcutta warns: “If we don’t declare an emergency now it will be another 15 years before anything is done. By that time there could be an epidemic of cancer.”

Abdul Wadud Khan, head of the Department of Occupational and Environmental Health at the National Institute of Preventative and Social Medicine in the Bangladeshi capital Dhaka, says that since 1993, when the problem was first identified in the country’s Nawabganj district, 849 cases of arsenic poisoning have been diagnosed in 23 districts in southwestern Bangladesh. Khan estimates that 16 million people are at risk in these districts, although no more than a fraction of the wells there have been tested.

YELLOW fever is considered one of the most terrible of all infectious diseases. It begins with flu-like symptoms of headache and fever, but jaundice and internal haemorrhage often develop. When this happens, victims begin vomiting blood. In at least a quarter of all cases, the patient slips into a coma and dies.

Yellow fever has for many years been confined mainly to western Africa and South America. However, five years ago there was an epidemic in western Kenya-the first in eastern Africa in 26 years. The virus has been present there ever since and experts fear that it is only a matter of time before it reaches Asia, carried by a mosquito or a victim across the Indian Ocean.

“The risk [to Asia] is probably the greatest it has been at any time over the past fifty years,” says Duane Gubler, director of the department of vector-borne infectious diseases at the National Center for Infectious Diseases in Fort Collins, Colorado. Doctors in India say that controls to prevent yellow fever entering the country are simply not functioning. With an unvaccinated population and the fact that the mosquito which carries the virus, Aedes aegypti, is very common in India, the disease could become rampant once it secured a foothold.

Planning for the worst

To prepare for what some officials see as yellow fever’s inevitable march eastwards, the WHO is drafting a contingency plan in case there is a major urban outbreak. But in India itself, infectious disease experts say nothing is being done to avert an epidemic. “I have been shouting from the rooftops [for the government] to do something,” says Kalyan Banerjee, director of the National Institute of Virology in Pune. He is calling for money for research and a proper surveillance programme.

“Of all Asian countries, India is probably most at risk because Indian emigrants have moved to Africa and Latin America to set up businesses and there are all sorts of transport links as people move back and forth,” says Thomas Monath, a world authority on yellow fever and vice-president of OraVax, a biopharmaceuticals company based in Cambridge, Massachusetts.

The risk is heightened by weak health controls at India’s borders. International guidelines call for ports and airports to be kept free of A. aegypti, while all airplanes leaving areas where yellow fever is endemic have to be sprayed with insecticide. A ship that has at least one case of yellow fever on board, or that carries A. aegypti and arrives within 30 days of leaving an infected area must also be cleaned of insects.

Health authorities in India say the country has adopted these rules but critics claim they are rarely enforced. Indeed, a study published last year in a WHO journal confirmed what most travellers already knew: that the airports and ports of Bombay are infested with mosquitoes. The number of mosquitoes at the city’s ports had quadrupled compared with previous investigations.

Two international shipping companies which routinely stop at east and west African ports before arriving in Bombay told żěè¶ĚĘÓƵ that their journeys take less than 30 days but the vessels are never inspected for mosquitoes or fumigated. And at India’s international airports, health controls take a back seat to speeding up immigration procedures in order to encourage tourism. Ten years ago poorly-trained immigration authorities took over from the health ministry the role of screening travellers for yellow fever vaccination certificates. Before the switch, hundreds of people who arrived in Delhi without proof of vaccination from countries where the disease was endemic were sent into quarantine annually, compared with just a few in recent years.

Quarantine is the health authorities’ strongest tool-the maximum incubation period for yellow fever is six days, but the virus can be transferred by airplane from Africa to India in a matter of hours. Relaxing these controls could leave the door wide open for yellow fever and other diseases. “There is a definite, well-defined system but it needs to be strengthened,” admits S. P. Agarwal, India’s director-general of health services.

As well as improving health controls at ports and airports, experts say there is an urgent need to control mosquito breeding in Asia. The ravages of mosquito-borne epidemics were highlighted last year when an outbreak of dengue fever in Delhi affected an estimated 10 000 people, of whom 400 died. The virus was not even identified in a laboratory until the epidemic was on the wane. V. P. Sharma, director of the Delhi-based Malaria Research Centre, which is part of the Indian Council of Medical Research, says mosquitoes are out of control in many large Indian cities. “There should be good vector control in airports and ports but this is not done here or in many other Asian countries,” he says.

In Africa and South America, yellow fever is mainly confined to rural areas. The prospect of a yellow fever epidemic spreading through any of the developing world’s mega-cities, where few people have been vaccinated, sends shivers down the spines of tropical medicine experts (żěè¶ĚĘÓƵ, “Fever in the urban jungle”, 16 October 1993, p 25). In the jungles of South America, up to 80 per cent of the population has been vaccinated. But in some parts of the continent, and in much of Africa, the immunisation rate is much lower, and the problem of unimmunised migratory workers moving from rural areas to coastal cities is growing.

Out of Africa

The number of people around the world being infected with yellow fever is increasing, mainly because of its resurgence in western Africa. Between 1986 and 1995, some 23 500 new cases-mostly in Nigeria-were reported to the WHO, compared with 4200 in the previous 10 years. The actual number of new cases, however, is thought to be much higher-around 200 000 annually. Countries are reluctant to report yellow fever because of the threat of travel restrictions, such as quarantine, and the negative effect that epidemics can have on trade and tourism. Nigeria reported about 20 000 cases between 1985 and 1996 but the actual number is thought to be closer to one million, of which one-fifth died. In all, 91 per cent of the world’s cases are in Africa.

There are factors that could temper the threat. The disease occurs mainly in the countryside, where conditions are best for mosquitoes to breed, and especially in forested areas that are inhabited by monkeys, which are hosts for the disease. There have been no outbreaks in coastal areas of western Africa and Latin America for 50 years. Furthermore, there has never been a case in cities on the east coast of Africa, which would be the most worrying for India. But large cities in Africa, such as Lagos, are at risk because vaccination levels are low. The disease has hit hardest in recent years in Nigeria, Ghana and Mali, where vaccination levels are between 1 and 22 per cent.

Indeed, virologists are puzzled as to why yellow fever has apparently not yet reached Asia, and there are burning questions about how easily the virus could spread if it did get there. “Less and less research is done on yellow fever and fewer and fewer virologists are working in tropical medicine despite all the talk about re-emerging diseases,” warns Monath. Studying how susceptible Asians are to yellow fever and how competent the local type of A. aegypti is for carrying the virus are “fertile fields for research”, he says.

Some evidence suggests that an outbreak of yellow fever in Asia would not be as deadly as it is in Africa or Latin America. Yellow fever is a flavivirus like dengue fever and it is thought that antibodies to other flaviviruses may offer some protection to yellow fever, although the reverse is not true. In the 19th century, for instance, it was noticed that British troops in Gibraltar who had served in India, where dengue is widespread, were less susceptible to yellow fever. Experiments carried out in the 1970s on monkeys suggested that immunity to dengue reduces the severity of yellow fever symptoms.

About 60 per cent of all dengue cases worldwide occur in southeast Asia. This could mean that yellow fever may have reached Asia in the past but wasn’t recognised, suggests Gubler. “It may have been introduced . . . but just died out,” he says. There is also some experimental evidence that suggests Asian A. aegypti may not be as efficient at carrying the yellow fever virus as those in Africa.

Whatever the likelihood of yellow fever gaining a foothold in Asia, “good surveillance is needed in India to monitor these kinds of diseases so early detection is possible,” says Gubler. This could be done using relatively inexpensive laboratory techniques to routinely identify the types of viruses circulating in cities like Delhi. But Indian experts remain pessimistic about the prospects of avoiding future epidemics. “Doctors are failing to identify and treat malaria, never mind discussing yellow fever,” warns Sharma.

A SERIES of arguments between Indian states over the sharing of water
from their rivers has paralysed dam projects across the country.

This week the Supreme Court in Delhi will hear a case concerning the
controversial, partly built dam on the Narmada river in the state of Gujarat.
The case was originally brought by the environmental organisation NBA, or Save
the Narmada, which wants to force the Indian government to re-evaluate the
project. Construction was halted in 1995 pending the outcome of the hearing.

Now Gujarat is in dispute with its neighbour, Madhya Pradesh, over the dam’s
eventual height—should the Supreme Court allow work to restart. Both
states have filed petitions requesting the court to rule on their dispute as
part of the case.

Madhya Pradesh, which is upstream of the dam, wants its final height to be
lowered by 5 metres. While this would cut its electricity generating capacity by
10 per cent, it would allow 11 000 people to remain on land that would otherwise
be flooded. But Gujarat says its needs for irrigation and energy should come
first.

When building work on the Narmada dam began, it was the focus of huge
domestic and international opposition, fuelled by concern over environmental
damage and the large number of people who would be flooded out of their homes.
The dam now stands about 80 metres high. If it is built to its planned 138
metres, an estimated 43 000 people will have to be relocated and paid
compensation.

Madhya Pradesh says it is prepared to accept less power from the dam if its
height is reduced. Gujarat has responded with an advertising campaign depicting
drought-stricken areas, under the caption: “Give us water, or we will die.”

The sharing of resources from India’s rivers is usually decided by water
tribunals. The government’s plans for the Narmada dam stem from a 1979 tribunal
decision, which critics say is now out of date. For instance, the tribunal said
that just 7000 people would be affected by the dam.

“There should be a pause and the project should be re-examined,” argues
Ramaswamy Iyer of the Centre for Policy Research in Delhi, and a member of a
panel that studied the project for the government and the court. “We can’t just
dynamite it, so we should see what benefits can be obtained while minimising the
adverse effects.”

Meanwhile, in southern India, where river water is scarcer, simmering
disputes are erupting with new passion. The states of Andhra Pradesh and
Karnataka are at loggerheads over the height of the Alamatti dam on the Krishna
river. In a Supreme Court case filed last month, Andhra Pradesh, which is
downstream of the dam, claims that the dam’s top 5 metres could rob it of water
that it is entitled to under a 1976 water tribunal decision. Karnataka says that
it has rights to the disputed water, but that in any case the extra height will
be used only for power generation. The extra water will still flow down the
river, Karnataka claims.

Mohan Katarki, a lawyer representing Karnataka, says: “Water disputes, if not
attended to, will become a major headache for the stability of Indian
˛ő´Çł¦ľ±±đłŮ˛â.”

CRITICS of a controversial technique for sterilising women are preparing
to take the Indian government to court for turning a blind eye to its use in a
number of Indian cities. The government has not approved the method, yet trials
of the technique are going ahead under the auspices of nongovernmental
organisations.

In the procedure pellets containing quinacrine, an antimalarial drug, are
inserted into the upper part of the woman’s uterus. The resulting inflammation
blocks the Fallopian tubes with scar tissue.

Some doctors fear that quinacrine could cause cancer. They point to a 1994
ruling from the special programme on research in human reproduction (HRP), based
at the WHO’s headquarters in Geneva, which said that quinacrine sterilisation
should not be used until animal toxicity studies are completed. The alarm was
sounded by experiments showing that quinacrine can cause mutations in cultured
cells.

“Nothing has changed since then to alter our opinion that it is premature for
large-scale human studies,” says Patrick Rowe, a medical officer at the HRP. But
supporters of the method say that some 100 000 women in developing countries
have been safely given the procedure.

In India, the leading advocate of quinacrine sterilisation is J. K. Jain, a
surgeon who runs a private hospital in Delhi and sits in the Indian Parliament
for the Hindu nationalist BJP. He claims that the technique is a safe and
effective way to curb India’s population growth because it involves no surgery
and can be administered by rural healthcare workers. It is also cheap. A dose of
seven pellets costs about $1, says Jain. “The WHO is committing a
treacherous act against poor countries by not conducting trials,” he says.

Although quinacrine sterilisation has not been approved for use in India,
privately run trials are going ahead. An organisation called the International
Federation for Family Health, based in Research Triangle Park, North Carolina,
headed by gynaecologist Elton Kessel, is supplying quinacrine and supporting
planned or ongoing trials in Bangalore, Vadodara, Patiala and Ranchi. Jain is
the international president of this organisation.

The quinacrine pellets are manufactured by a Swiss company called Sipharm.
Fritz Schneiter, Sipharm’s commercial director, told żěè¶ĚĘÓƵ that
he was unaware of the HRP’s guidance that quinacrine should not be used for
sterilisation.

Biral Mullick, a gynaecologist in Calcutta, used the method for many years.
Mullick says that he has sterilised some 10 000 women—but he adds that he
stopped using quinacrine five months ago on orders from the West Bengal state
authorities.

A spokesman for the Indian Ministry of Health and Family Welfare says that
the country’s drugs controller has ordered an investigation into whether
quinacrine sterilisation is being used. But following reports that trials are
spreading to other cities, opponents of the method are now turning to the law to
force the government to ban quinacrine trials.

Mohan Rao of the Centre of Social Medicine and Community Health at Jawaharlal
Nehru University in Delhi has teamed up with medical colleagues and the All
India Democratic Women’s Association to take the government to court. Rao claims
that doctors who are helping with the trials are ignorant of the treatment’s
possible side effects. “They are getting involved without knowing anything about
it,” he says.

Quinacrine sterilisation was developed by a Chilean scientist, Jaime Zipper,
in the 1970s. Between 1989 and 1992, doctors in Vietnam sterilised more than 30
000 women using the technique. This programme has been halted. But Kessel claims
that the urgent need for population control in rural India justifies its
continued use.

In many parts of India, up to 5 women die in labour for every 1000 births,
Kessel says. Sterilising 1000 women prevents around 2000 births, he says, “and
that saves the lives of 10 women”. Kessel argues that Chilean studies show the
risks of the treatment are lower than those of childbirth.

But the majority of experts support the HRP’s position. Theodore King,
president of Family Health International, another reproductive health
organisation based in Research Triangle Park, agrees that there is no proof that
quinacrine causes cancer. But assessing the risk will require animal experiments
costing some $8 million. “Until those studies are done, it should not be
used clinically,” says King.

DELHI’s reputation as one of the world’s filthiest cities has grown with
claims that the city’s drinking water contains alarmingly high levels of
pesticides and heavy metals. The details emerged in a High Court lawsuit filed
earlier this month demanding action over pollution in the city’s Yamuna
River.

The latest lawsuit follows widespread concern about the quality of Delhi’s
air, which is laden with particulates from traffic emissions (This Week, 8
March, p 9).

Lawyer B. L. Wadehra, who brought the new case to court, claims pesticides
used on farmland in the upstream state of Haryana are to blame for much of the
pollution. At the first hearing, judges ordered central and local authorities to
report back in May on the concentrations of toxins in the river and the
tributary canals which provide water to farms and three-quarters of Delhi’s 11
million inhabitants.

Wadehra’s evidence of high levels of heavy metals and pesticides, including
DDT, in the river water comes from a report by the Centre for Science and
Environment, an environmental organisation based in Delhi. The centre reviewed
the findings of pollution control authorities and academics. Its report
says that concentrations of these substances has reached alarming levels, which
could cause health problems. Indian regulations state that drinking water should
contain no detectable DDT. Yet in July 1995, one study recorded a concentration
of 203 nanograms per litre in water extracted for drinking.

The local governments in Delhi and the Haryana and Uttar Pradesh provinces
upstream are installing about 35 treatment plants for sewage which currently
flows directly into the Yamuna. This follows a series of Supreme Court rulings
in another lawsuit on river pollution which began in 1985. The court also
ordered Delhi’s industrial plants to treat their effluent.

But even when the new treatment plants are working, says Rajendra Sharma of
India’s environment ministry, the main channel of the Yamuna will still not be
fit for bathing. “For all practical purposes you can’t call the Yamuna a river.
It’s dead,” he says. “Until we get fresh-water flowing into it there can be no
talk of revival.”

Most of Delhi’s drinking water comes from a canal that runs east of the
river, but which flows through farmland before entering the city. This water is
not tested regularly for pesticide residues. A second, western canal provides
water for farming and industrial areas of Haryana. The two canals divert almost
all of the Yamuna’s flow except during the monsoon months. During the dry
season, only sewage and industrial waste flow along the river near Delhi.

Wadehra complains that previous court cases have not addressed the problem of
river pollution from agricultural run-off. “If farmers are using pesticides
to increase production, someone has to see that these don’t get into the river
water I’m drinking,” he says.

RESIDENTS of Delhi are exposed to at least seven times the maximum level
of particulate pollution recommended by international health standards,
according to a study by India’s Central Pollution Control Board. The figures are
the first to estimate exposure rather than ambient levels of pollutants.

Between October and December last year, the board measured levels of
suspended particulate matter (SPM) in homes, offices and a school in four
neighbourhoods in east Delhi, and along the roads that residents use to travel
to work. Monitoring on the streets of Delhi has previously indicated that the
city is one of the most polluted in the world, but no one knew exactly how much
of the pollution was inhaled.

The authors of the study conclude that air pollution in Delhi has reached
“such an alarming stage” that only radical measures, such as removing a third of
all vehicles from the roads and staggering working hours, will reduce it to safe
levels. They want air pollution to be halved to stop the rise in respiratory
disorders.

The researchers recorded daily average SPM concentrations in homes of 363 to
751 micrograms per cubic metre, depending on the neighbourhood. The Indian air
quality standard for SPM over a 24-hour period is 200 micrograms per cubic
metre.

To estimate people’s actual exposure to SPM, the researchers asked 1009
residents to give an account of their typical daily activities. The results
ranged between those for children, mostly staying indoors, who were breathing
air with an average of 388 micrograms of SPM per cubic metre, to students, who
commute along the city’s main roads and inhale an average of 960 micrograms of
SPM per cubic metre throughout the day.

Such findings are normally expressed in the standard units used by the WHO,
which measure total daily exposure, and range from 9.3 milligram-hours per cubic
metre for the children and 23 mg-hours per cubic metre for the students. The
WHO’s maximum limit for daily exposure to SPM is 1.2 mg-hours per cubic metre
for children and 3.0 mg-hours per cubic metre for adults. About one-quarter of
the residents interviewed reported having severe respiratory disorders.

J. S. Kamyotra, coordinator of the project, says that the study is more
accurate than past attempts to measure pollution exposure, which have relied on
ambient air quality measurements from outdoor monitoring stations.

A FLEET of motorised rickshaws that run on propane will be launched onto
the streets of Delhi next month in a bid to reduce air pollution. Just 50 of the
shiny green and yellow three-wheelers will compete with the city’s 70 000 black
and yellow petrol-engined models in the first experiment of its kind in the
world.

The rickshaws will be fitted with propane conversion kits made by an
Indo-Canadian company called G&T Yugo Tech, which will allow conventional
petrol engines to run on propane. Each kit includes a 12-litre tank and a
microprocessor to control the oil used by the engine.

Conventional motorised rickshaws, with their two-stroke engines, are among
the most polluting vehicles known. At present they give off ten times as much
hydrocarbon pollution as four-stroke engines. And rickshaw drivers usually try
to save petrol by diluting it with diesel, which creates even more
pollution.

Rajiv Savara, managing director of G&T Yugo Tech, says that running
rickshaws on propane cuts hydrocarbon, carbon monoxide and nitrogen oxide
emissions by more than 40 per cent. Engine performance is unimpaired, or even
improves.

Use of alternative fuels such as propane is currently restricted in India by
laws imposed during previous shortages. But the idea now has the backing of the
Supreme Court, which last December ruled that the Delhi government was failing
to curb air pollution. G&T Yugo Tech told the court that its propane
rickshaws could help solve the problem and offered to pay for a trial. The court
ordered the central and local governments to allow the experiment and monitor
the results.

Savara says that equipping each rickshaw with a propane tank will
cost about 12 000 rupees (ÂŁ200), a sum most rickshaw owners would be
unwilling to pay and which the poorer drivers could never afford. One proposal
to finance a transition to propane, if the trial is a success, is for the
government to buy the kits and recover the investment by taxing the fuel.

Propane could be sold to rickshaw drivers at about half the cost of
petrol, Savara says, saving them about 40 per cent on operating costs before any
tax is levied. “At the end of the day they would be making 50 to 100 rupees
(£0.85 to £1.70) more, which is a lot of money for them.”