health effects of arsenic exposure in bangladesh
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HEALTH EFFECTS OF
ARSENIC EXPOSURE IN
BANGLADESH
Manzurul H Khan Assistant Prof, OEH, NIPSOM
&
Prof Sk Akhtar Ahmad Professor OEH & Ex Director NIPSOM
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Individuals are exposed to arsenic from various sources like
occupational settings, medicines, air, water and food.
Chronic exposure to arsenic has long since been linked to
adverse health effects including cancers in human populations.
Arsenic is a known carcinogen and has potentialities ofproducing cancers at multiple sites, notably in the skin, bladder,
kidneys, prostate and lungs.
(World Health Organization. Environmental Health Criteria 18: Arsenic. Geneva,Switzerland: World Health Organization; 1981.)
ARSENIC AND ARSENIC COMPOUNDS. Environmental Health Criteria 224. WHO. 2001http// whqlibdoc.who.int/ehc/WHO_EHC_224.pdf
ATSDR. Toxicological Profile: Arsenic. Agency for Toxic Substances and Disease Registry
(ATSDR). 2007. Toxicological profile for Arsenic. Atlanta, GA: U.S. Department of Health and
Human Services ...www.atsdr.cdc.gov/toxprofiles/tp2.html.
Arsenic in drinking water.
National Research Council. National Academy of Sciences. 1999.National Academy Press. Washington DC. 310pp.
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Lifetime exposure to arsenic in drinking water, at a
concentration of 0.2 mg/L would result in a cumulative
skin cancer risk of 5%.
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Non-cancer health effects of arsenic includes:Pigmentary changes of the skin
(melanosis & leucomelanosis)
Keratosis of palms and soles;Respiratory illnesses;
Hypertension;
Diabetes mellitus;
Neurological effects;
Adverse reproductive effects(ed fetal, natal &neonatal mortalities;
ed low birth weight,
spontaneous abortions, preterm births,
stillbirths and pre-eclamsias; and
congenital malformations);Cardiovascular and cerebrovascular diseases and mortalities;
Peripheral vascular disease;
Hepatopathy;
Nephropathy;
Enhanced rate of mortalities from all causes.
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In Bangladesh exposure to arsenic are through water & food.
3577 million of roughly 125 million inhabitants of Bangladeshhave been drinking the contaminated well water.
Working with a consensus case definition & case diagnosis
algorithm Arsenic Cell at DGHS till June 2009 has clinically
confirmed ~46000 arsenicosis cases in Bangladesh.
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Many of the health problems known to be related to arsenicexposure ranging from the classical dermatological signs
(melanosis, keratosis, & leucomelanosis) to :
Respiratory problems,
Malnutrition, anemia, weakness,
Diabetes mellitus, Hypertension,Hepatopathy,
Peripheral neuropathy,
Conjunctival congestion,
Oedema of lower limbs,
Adverse reproductive outcomes,
Gangrene, and
Skin cancers.
Manifestations already evident amongst the
arsenic exposed population in Bangladesh
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Spotted Melanosis
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Spotted Melanosis
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Spotted Melanosis & Leukomelanosis
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Leukomelanosis
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Moderate Keratosis
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Severe Keratosis of Sole
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Severe Keratosis of Sole
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Severe Keratosis of Palm
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Severe Keratosis of Palm
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Non-pitting Edema of leg
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Bowens Disease
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Gangrene of Foot
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Gangrene of Foot
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Squamous Cell Carcinoma in the Scalp
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Squamous Cell Carcinoma in palm
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NCDsNCDs the prevalence ratios forhypertension adjusted for age,
sex, and body mass index were 1.2, 2.2, 2.5 and 0.8, 1.5,
2.2, 3.0, in relation to arsenic exposure in milligrams per
liter and milligram-years per liter, respectively.
Age, sex, and BMI adjustment prevalence ratio fordiabetes mellitus among keratotic subjects exposed to
arsenic was 5.2 (95% confidence interval 2.5-10.5)
Rahman M, et al. Hypertension and Arsenic Exposure in Bangladesh.Hypertension. 1999;33:74-78.
Rahman M, et al. Diabetes Mellitus Associated with Arsenic Exposure in Bangladesh.Am J Epidemiol
1998;148:198-203.
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Reproductive healthReproductive health Adverse pregnancy outcomes in terms ofspontaneous abortion,
stillbirth, and preterm birth rates were significantly higher in theexposed group than those in the non exposed group (p= 0.008, p= 0.046, and p= 0.018, respectively). matched the women in bothexposed and non exposed groups for age, socioeconomic status,education, and age at marriage. [Ahmad SA, et al. 20012001].
An increased risk ofstillbirth is associated with arseniccontamination. This risk, substantial enough to be detected by anecological approach and not readily attributable to unmeasuredconfounding, is essentially preventable and all efforts must bemade to protect women at high risk.
Ahmad SA et al. Arsenic in drinking water and pregnancy outcomes. Environ. Health. Perspect. 2001,
109, 629-631.
Milton AH, et al . Chronic arsenic exposure and adverse pregnancy outcomes in Bangladesh.
Epidemiology2005, 16, 82-86.
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Statistically significant association between arsenic exposure and birth-
defects (odds ratio=1.005, 95% CI 1.001-1.010) reported by Kwok RK,
et al 2006.
A trend ofreduced birth weight in relation to arsenic concentrations in
drinking water (below 100 g/L). [cohortstudy: Rahman A, et al. 2009].
Kwok RK, et al. Arsenic in Drinking-water and Reproductive Health Outcomes: A Study of
Participants in the Bangladesh Integrated Nutrition Programme. J HEALTH POPUL NUTR 2006;
24(2):190-205.
Cherry N, et al. Stillbirth in rural Bangladesh: arsenic exposure and other
etiological factors: a report from Gonoshasthaya Kendra. Bulletin of the World Health Organization
2008;86:172177.
Rahman A, et al. Association of Arsenic Exposure during Pregnancywith Fetal Loss and Infant
Death: A Cohort Study in Bangladesh. Am J Epidemiol. 2007;165:13891396
Drinking tube-well water with more than 50 g/L of arsenic per liter
during pregnancy significantly increased the risks offetal loss(relative risk =1.14, 95% CI: 1.04, 1.25) and infant death (relativerisk =1.17, 95% CI: 1.03, 1.32). There was a significant doseresponse of arsenic exposure to risk of infant death (p =0.02)[cohortstudy: Rahman A, et al. 2007].
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At low level of arsenic exposure, significant negative dose
effect of prenatal arsenic exposure on birth weight, head
circumference, and chest circumference was observed.
The effects on birth size found were robust to adjustmentfor confounding effect, and the effect estimate observed
has public health significance (Rahman A, et al 2009)
Rahman A, et al. Arsenic Exposure During Pregnancy and Size at Birth: A Prospective Cohort
Study in Bangladesh. Am J Epidemiol 2009;169:304312.
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increasing evidence has raised awareness of the effect of the intrauterine
environment on adult-onset diseaseseg, in mice the incidence of cancers is
elevated among offspring exposed to arsenic in utero;5 the findings of a recent
ecological analysis from Chile support this possibility.6
Rahman A, Vahter M, Smith AH, et al. Arsenic exposure during pregnancy and size at birth: a prospective
cohort study in Bangladesh. Am J Epidemiol 2009;169:30412.5. Waalkes MP, Liu J, Diwan BA. Transplacental arsenic carcinogenesis in mice. Toxicol Appl Pharmacol 2007;222:27180.6. Liaw J, Marshall G, Yuan Y, Ferreccio C, Steinmaus C, Smith AH. Increased childhood liver cancer mortality and arsenic in
drinking water in northern Chile. Cancer Epidemiol Biomarkers Prev 2008;17:198287.
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NutritionNutrition Lower Body mass index (BMI) was reported among the
arsenicosis patients compared to the unexposedpopulation in a previous study in Bangladesh (Milton AH,
et al. 2010).2010).
Women exposed to arsenic >50 g/L were at 1.9 times
(OR = 1.9, 95% CI = 1.13.6) increased risk of malnutrition
compared to unexposed. Chronic arsenic exposure is likely
to contribute to poor nutritional status among women of
2045 years. (Milton AH, et al. 2010)2010)
Milton AH, et al. Association between nutritional status and arsenicosis due to chronic arsenic
exposure in Bangladesh. Int. J. Environ. Health Res. 2004, 14, 99-108.
Milton AH, et al. Association between Chronic Arsenic Exposure and Nutritional Status among the
Women of Child Bearing Age: A Case-Control Study in Bangladesh. Int. J. Environ. Res. Public Health2010, 7, 2811-2821.
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MortalityMortality
An increase of nearly 70% in all-cause mortality was noted
among those exposed to the highest concentration of
arsenic in water (15018640 g/L) relative to those
exposed to not more than 100 g/L.
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ARSENICOSIS PATIENT Management:ARSENICOSIS PATIENT Management:
Current practice In BangladeshTill date there is no specific treatment of
chronic arsenic toxicity in human health.
Stoppage of further intake of arseniccontaminated water;
Supportive Treatment
Increased intake of available proteins & vitamin
rich vegetables
Application of keratolytics for keratosis;
Symptom/manifestation specific management.
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Retinol
Beta-carotene
Ascorbic acid
Alpha-tocopherol Selenium
Spirulina
Zinc
Treatment of ArsenicosisTreatment of Arsenicosis
Treatment with these antioxidants require 4-12months. Prolong duration of treatmentinfluences the compliance and treatment cost
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Food supplementsFood supplements
Protein and vitamin rich foodProtein and vitamin rich food
supplementation is helpful in early recoverysupplementation is helpful in early recovery
of symptoms. A ready reference of locallyof symptoms. A ready reference of locallyavailable protein and vitamin rich food itemsavailable protein and vitamin rich food items
are given below:are given below:
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Food supplements contdFood supplements contd