ITREOH currently concentrates activities in India on:
1) arsenic in drinking water, and 2) indoor air pollution, including its
impact on the incidence of tuberculosis.
quicklinks:
arsenic in drinking water
Study contact: Dr.Allan
H. Smith (Program Director)
Principal
Investigator of Arsenic Studies
The largest reported population exposed to arsenic-contaminated groundwater
resides in West Bengal, India and neighboring Bangladesh. Here in the Bengal Basin,
an estimated 800,000 inhabitants are drinking contaminated groundwater in
West Bengal, India, while several millions are exposed in neighboring Bangladesh.
Early manifestations of long-term arsenic exposure include skin keratoses
and hyperpigmentation. These skin lesions pose a serious public health
problem because advanced forms of keratoses are painful, and may increase
susceptibility to respiratory effects and later cancer risks.
Hyperpigmentation is marked by raindrop-shaped discolored spots, diffuse
dark brown spots, or diffuse darkening of the skin on the limbs and trunk.
Simple keratosis usually appears as bilateral thickening of the palms and
soles, while in nodular keratosis, small protrusions appear on the palms
and soles, with or without nodules on the dorsum of the hands, feet, or the
legs. In contrast to cancers, which take decades to develop, these skin
lesions are generally observed five to ten years after exposure commences.
Other health effects from ingestion of arsenic-contaminated drinking water
include weakness, conjunctival congestion, hepatomegaly, portal
hypertension, respiratory system effects such as bronchiectasis,
polyneuropathy, solid edema of limbs, and malignant neoplasms of skin,
bladder and lung.
The arsenic problems in West Bengal and Bangladesh have created a major
need for skilled environmental health professionals in a region where scant
training opportunities were previously available.
The ITREOH program begins to address these issues with a
multidisciplinary approach -- training in a wide range of disciplines,
including epidemiology and risk assessment, analytical chemistry, and
population exposure assessment. Skills developed by the program to combat
this crisis range from investigations of nutritional susceptibility to
preventive action and evaluation of public health interventions.
Some recent projects include:
Studies of arsenic-induced skin lesions and dietary susceptibility
in West Bengal, India
In collaboration with Professor D.N. Guha Mazumder, in which data from a
large cross-sectional survey of about 7000 people in an arsenic exposed
region in West Bengal was analyzed. The
dose-response analysis linking cases of skin keratoses and
hyperpigmentation to arsenic water levels was completed and published.
This work led to the following subsequent projects.
Dose Response and Susceptibility Investigation of Skin
Keratoses and Hyperpigmentation due to Ingestion of Arsenic in Drinking
Water in West Bengal
The first detailed investigation of the dose-response relationship of
skin lesions and arsenic in drinking water was completed by our group,
including trainees in Kolkata. The investigation focused on the 280 people
with skin lesions from the prevalence study who were exposed to drinking
water containing less than 500 µ g/L of inorganic arsenic. This was the
first detailed study to investigate dose-response relations using a refined
exposure assessment which incorporated past arsenic exposures. Dietary and
physical exam data, as well as water, blood, and urine samples, were
collected from all cases and compared to matched controls. The key
objective was to characterize the dose-response relationship, and to
determine if susceptibility to the arsenic-induced skin lesions varies by
arsenic methylation capability or certain nutritional factors. Several
publications that involved Fogarty trainees resulted (Chung
et al. 2006; Haque et
al. 2003; Mitra
et al. 2004) and further publications with trainees are being prepared.
Nested cross-sectional study of respiratory disease in highly
exposed patients with arsenic-caused skin lesions
The aim of this study in West Bengal
was to investigate chronic pulmonary disease, arsenic-caused skin lesions,
and nutritional susceptibility factors in a cross-sectional study with
follow-up investigations of prognosis. This study involved re-contacting
all participants in the
cross-sectional study who were found to have keratoses and/or
hyperpigmentation, and who apparently consumed water containing more than
500 µg/L of arsenic, plus a re-survey of a one-to-one matched random sample
of non-cases with low levels of arsenic in drinking water. Each subject is
interviewed in detail about present and past water sources, urine samples
were collected for arsenic methylation studies, blood samples for
micronutrient analysis, family nutrition is assessed, and respiratory
function measured with a portable spirometer. Two major publications have
resulted so far which include Fogarty trainees (Guha
Mazumder et al. 2005; von
Ehrenstein et al. 2005) .
Arsenic in drinking water, pregnancy outcomes, and child
development in West Bengal
Extensive studies have been conducted of ingestion of inorganic arsenic
in drinking water and health effects in adults. So far, little has been
done to investigate reproductive effects in pregnancy and effects on child
development. The goal of this
study was to investigate fertility, pregnancy outcomes (including
spontaneous abortion and stillbirths) and child development in a
retrospective study of a group of 100 women already known to have been
drinking water containing more than 400 ug/L of arsenic when surveyed in
1995. These women were compared with 100 women whose drinking water
contained less than 50 ug/L of arsenic. Fertility was assessed based on number
of pregnancies and spacing between pregnancies. Pregnancy histories were
used to compare spontaneous abortion and stillbirth rates between exposed
and unexposed mothers. Living children now aged 5-15 had a medical
examination and their cognitive abilities and learning achievements were
assessed with structured, culturally adapted testing methods. Detailed
nutritional assessment of each family was undertaken to search for a
potential effect modifying role of nutrition on arsenic effects.
Methylation patterns of arsenic as reflected in urine samples will be
assessed, for women and children in the study, to identify metabolic
susceptibility. One major publication involving Fogarty trainees, reporting
a marked increase in stillbirths, has been published
and other papers with trainees are currently being finalized and submitted.
Studies in Bangladesh
Groundwater used for drinking has been found to be contaminated with naturally
occurring inorganic arsenic in this country neighboring West Bengal, India.
It is estimated
that 57 million of the 125 million inhabitants of Bangladesh are at risk of drinking
contaminated water. The scale of this environmental disaster is greater
than any seen in recent history, beyond the accidents at Bhopal,
India, in 1984 and Chernobyl, Ukraine, in 1986.
In 2000, we
published a paper suggesting guidelines for responding to a population
exposure to arsenic, based upon several visits to Bangladesh by Dr. Allan Smith as a consultant for the World Health
Organization (WHO) between 1997 and 1998. This paper presented the Bangladesh
history of the discovery of arsenic in drinking water and recommended
intervention strategies. Tubewells were inserted to provide “pure
water” to prevent morbidity and mortality from gastrointestinal
disease. The water from these millions of tubewells was not tested for
arsenic contamination. Studies in other countries with long-term exposures
indicate that 1 in 10 persons that drink water containing 500 ug of
arsenic/liter may ultimately die due to arsenic-caused cancers including
lung, bladder and skin cancer. The rapid allocation of funding and prompt
expansion of current interventions should be facilitated. The fundamental
intervention is the identification and provision of arsenic-free drinking
water sources. We are currently seeking funding for a collaborative study
on children in Bangladesh,
which would include trainees.
Indoor Air
Pollution in India
Study contact: Dr.Kirk R.
Smith (Associate Director)
Principal
Investigator of Indoor
Air Pollution
Studies
Indoor air pollution from combustion of solid fuels (such as wood, crop
residues, animal dung, grasses, and coal) for cooking and space heating is
one of the ten most important risk factors in the global burden of disease.
In poor developing countries, indoor smoke from solid fuels accounts for an
estimated 3.7 percent of the total disease burden. In India,
approximately 80% of the population uses biomass fuel for cooking and
heating.
The research and training activities in the indoor air pollution program
emphasize the development of skills necessary to address environmental
health problems in India
and Nepal
resulting from exposure to indoor air pollution. Researchers from India and Nepal
attend Fogarty-sponsored trainings in South Asia and, in some cases, are
selected to spend a semester at the University
of California, Berkeley. Trainees selected to visit the
university work with faculty members in the School of Public Health
to receive specialized training in exposure assessment and advanced
epidemiologic methods.
Some recent projects include:
Air pollution exposure atlas for India
There have been several publications and activities to help set the
stage for development of a national air pollution exposure atlas for India.
1. A global
database of indoor air pollution studies was jointly published with
WHO.
2. Studies
were initiated along with the World Bank office in Delhi to field test measurement and
modeling techniques in Andhra Pradesh that might be used for a national
atlas.
3. UCB Fogarty collaborators in India have piloted specific
simplified IAQ measurement methods in four Indian states that might be used
as part of a planned national household survey.
Exposures to respirable particulate matter associated with household
fuel use
This
study, part of the activities pursuant to creating a national exposure
atlas, quantified the daily average concentrations of respirable
particulates.
Health impacts of indoor air pollution evaluated via national
household survey databases
Conducted jointly with Indian collaborators and the East-West Center in
Honolulu, this analysis examined the association between indoor air
pollution from combustion of unprocessed solid fuels (wood, animal dung,
crop residues, shrubs/grass, coal) for cooking and heating and selected
health outcomes in five countries—China, Georgia, India, Indonesia,
and Nigeria – in which the WHO had conducted large household surveys.
Indoor air pollution and cataracts
This study explored the relationship between indoor air pollution and
cataracts via a hospital-based case–control study conducted on the
Nepal–India border, providing conclusive evidence that use of solid
fuel in unflued indoor stoves is associated with increased
risk of cataracts in women who do the household cooking.
Indoor air pollution and tuberculosis
This multi-site proposal was developed during a two-week Environmental
and Occupational Epidemiology workshop
held in December 2003. After review and revision, four proposals were
chosen for the multi-center project: three in India
and one in Nepal.
Cases are restricted to women 20 years and older to minimize confounding
due to tobacco smoke and because their exposure to indoor smoke is likely
higher. Approximately 200 cases are being recruited at each site based on
diagnosis of active pulmonary tuberculosis at the hospital during a specified
period of time. Controls are selected from females who present to the
Medical, Surgical, or Gynecology departments of the participating medical
facilities for conditions unrelated tuberculosis, are sputum negative, and
have no recent history of tuberculosis.
A data analysis workshop was held August 14-18, 2006 in Chennai, India. Learn
more about the workshop, download presentations and view photos (coming
soon).
performance sites
| collaborating institutions
Arsenic Health Effects
Indian Institute of Chemical Biology
Dr. Ashok Giri
(Assistant Director)
(p) 91-33-2473-6793 (f) 91-33-2414-7594
4, Raja
S.C. Mullick Road
Kolkata 700 032 INDIA
Indoor Air Pollution
Sri Ramachandra University
Dr. Kalpana Balakrishnan
(p) 91-44-476-5609 (f) 91-44-476-7008
1 Ramachandra Nagar, Porur
Chennai 600 116 INDIA
