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DR S D GAUR BEST PAPER AWARD ON ENVIRONMENTAL HEALTH
Year : 2018  |  Volume : 62  |  Issue : 3  |  Page : 182-187  

Exposure to indoor air pollution and its perceived impact on health of women and their children: A household survey in a slum of Kolkata, India


1 Junior Resident, Department of Preventive and Social Medicine, All India Institute of Hygiene and Public Health, Kolkata, West Bengal, India
2 Assistant Professor and Head, Department of Preventive and Social Medicine, All India Institute of Hygiene and Public Health, Kolkata, West Bengal, India
3 Director-Professor, Department of Preventive and Social Medicine, All India Institute of Hygiene and Public Health, Kolkata, West Bengal, India
4 Assistant Professor, Department of Preventive and Social Medicine, All India Institute of Hygiene and Public Health, Kolkata, West Bengal, India

Date of Web Publication12-Sep-2018

Correspondence Address:
Shobhit Garg
Room No. 204, All India Institute of Hygiene and Public Health, 110 C. R. Avenue, Kolkata - 700 073, West Bengal
India
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/ijph.IJPH_259_18

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   Abstract 


Background: One's house is believed to be the safest and the healthiest place to live in. Indoor air pollution (IAP) means the presence of unwanted substances in the indoor air at concentration toxic to health. Objective: The objective of this study is to study the presence of IAP, its associated factors and impact on health of women residing in an urban slum of Kolkata, West Bengal, India. Methods: It was a cross-sectional study done from January 2017 to March 2017 among 120 households of a slum. Data were collected using a pre-designed pre-tested schedule from the homemaker of the households. All analyses were conducted with R: A Language and Environment for Statistical Computing. Results: About 60% households used kerosene as cooking fuel predominantly. Smoke from the neighbouring houses troubled 57.5% respondents. More than 60% houses were overcrowded and more than 70% houses were poorly ventilated. IAP-related symptoms such as irritation in the eye, suffocation, dry cough significantly correlated with the presence of IAP sources and its contributory factors. Of 120, 78 (65%) perceived the presence of IAP in their houses. Lower per capita income (PCI), ground floor, and joint family were found to have higher odds of sources of IAP. Younger age, lower PCI, and ground floor were found to be strongly associated with higher contributory factors of IAP. Conclusion: The present study found that the majority of the households were exposed to IAP due to kerosene, neighborhood smoke while overcrowding and ill-ventilation accentuated it. Effective intervention with intersectoral coordination is the need of the hour.

Keywords: Indoor air pollution, perceived health, slum, women's health


How to cite this article:
Maharana SP, Paul B, Garg S, Dasgupta A, Bandyopadhyay L. Exposure to indoor air pollution and its perceived impact on health of women and their children: A household survey in a slum of Kolkata, India. Indian J Public Health 2018;62:182-7

How to cite this URL:
Maharana SP, Paul B, Garg S, Dasgupta A, Bandyopadhyay L. Exposure to indoor air pollution and its perceived impact on health of women and their children: A household survey in a slum of Kolkata, India. Indian J Public Health [serial online] 2018 [cited 2018 Dec 12];62:182-7. Available from: http://www.ijph.in/text.asp?2018/62/3/182/241092




   Introduction Top


One's house is believed to be the safest and the healthiest place to live in. However, the environment inside the house can also affect one's health adversely especially the air we breathe in. Indoor air pollution (IAP) means the presence of unwanted substances in the indoor air at concentration toxic to health. The World Health Organization (WHO) asserts the rule of 1000 which states that a pollutant released indoors is one thousand times more likely to reach people's lung than a pollutant released outdoors.[1]

The indoor air pollutants can be (i) Physical (dust, ash, and suspended particulate matter); (ii) Chemical (pesticides, insect repellants (IR), carbon monoxide (CO), and nitric oxides (NO2)); and (iii) Biological (bacteria, fungi, microbial spores, and animal dander). Principal sources of IAP include fuel combustion, building materials, bio-aerosols, and growing outdoor air pollution.[1] The unclean fuels used for cooking such as wood, biomass, and kerosene are at the bottom of energy ladder which produce a range of health-damaging pollutants such as fine particles, CO, NO2, sulfur dioxide (SO2), and benzene remains a major public health concern in the developing countries.[2],[3],[4] Apart from sources, there are certain factors which contribute to IAP such as poorly ventilated houses, overcrowding, presence of damp walls/roof, and poor housekeepings.[5],[6]

IAP is a key contributor to the global burden of diseases.[7] According to the WHO, about 4.3 million people a year die prematurely from illness attributable to the household air pollution.[8] Out of which 12% are due to pneumonia, 34% from stroke, 26% from ischemic heart disease, 22% from chronic obstructive pulmonary disease (COPD), and 6% from lung cancer. In the developing countries, the problem of IAP far outweighs the outdoor air pollution.[9],[10] India is one of the ten low- and middle-income countries where IAP is responsible for a total of more than 1.5 million deaths a year.[11] The Global Burden of Diseases, 2015 reports household IAP as the fourth leading cause of attributable Disability Adjusted Life Years in India.[7]

There is convincing evidence of the adverse effects of IAP on human health.[5],[12],[13] These effects may be short term or long term. Symptoms such as suffocation, burning eyes, and headaches pose as short-term problems. The long-term health effects though influenced by the time of exposure result in premature deaths from noncommunicable diseases.[14],[15]

The women and under-five children face a greater impact due to IAP as they stay indoors most of the time. In most societies, women are in charge of cooking spending 3–7 h/day near the stove.[13] Young children are often carried on their back or kept close to the warm hearth. Small particulate matter and other pollutants in indoor smoke inflame the airways and lungs, impairing immune response, and reducing the oxygen-carrying capacity of the blood leading to adverse consequences.[15] Thus, the children in the first few years of their lives are exposed to indoor smoke when their airways are still developing thereby making them vulnerable and susceptible to respiratory tract infections.[16],[17],[18] The use of kerosene as fuel has been found to be significantly associated with cough, bronchitis, and other chest illnesses.[19],[20]

More than 50% of premature deaths due to pneumonia among children under five are caused by the particulate matter (soot) inhaled from household air pollution.[8] There is also evidence of links between household air pollution and low birth weight, tuberculosis with allergic rhinitis and asthma due to indoor bioaerosols.[21]

IAP as a health problem and its deleterious effects are much neglected in the developing countries. There is a need to evaluate not only the presence of IAP but also whether the houses are well-ventilated or not, in which our women and children spend most of their time. Almost all types of indoor air pollutants especially cooking fuel and housing conditions are preventable, and IAP can be minimized. It is imperative to determine whether it is safe to breathe in the air inside their very own home.

With this backdrop, the present study was done to study the presence of IAP, its associated factors and their impact on health among the women residing in a slum of Kolkata, West Bengal, India.


   Materials and Methods Top


It was an observational cross-sectional study done from January 2017 to March 2017. The present study was done in a slum of Kolkata (Chetla) which is the service area Urban Health Unit and Training Center, Chetla, which is the urban practice field area of All India Institute of Hygiene and Public Health, Kolkata. It has 3 units with approximate 3000 households. A schedule was prepared including an observational checklist for assessing sources and contributory factors of IAP and attitude of women regarding IAP. This schedule was prepared using inductive (discussion with experts) and deductive (literature review)[5] approach both. Pretesting was done among 15 households, and necessary corrections were made. It was observed that surveying one household took 60–90 min. Therefore, researchers reached the conclusion that 120 households could be surveyed within the stipulated time frame. To cover the entire service area, it was decided to include 40 households from each unit. Families living in the slum for at least 1 year were considered for the study. For the study, researchers decided to consider women (homemaker) in the households as respondent because women spend most of the time indoors. Data were collected by door-to-door visit after obtaining informed consent from the women. If women in any household did not give written informed consent, then next household was approached. If any household was found locked on two visits on consecutive days, then next household was approached. No household was found without homemaker. To complete 120 households researchers visited 141 households, hence nonresponse rate was 15%.

Data were collected using a pre- designed pre-tested schedule which had six parts:

  1. Sociodemographic characteristics: Age, years of schooling, caste, religion, type of family, living arrangement (living at ground floor or not), and socioeconomic status using Modified B G Prasad scale, April 2016[22]
  2. Sources of IAP: Sources were enlisted as reported
  3. An observational checklist for contributory factors to IAP


    • Humid conditions such as damp walls, roof
    • Poor housekeeping
    • Poor ventilation (Window area <20% of floor area or absence of cross ventilation)[23]
    • Overcrowding (overcrowding was assessed using person per room criteria)[23]


  4. The frequency of acute respiratory tract infections (ARTI) among under-five children: Recent (last 15 days), past (last 1 year) (ARTI: Cough and difficult breathing as reported by the mother)[24]
  5. Perception of women about IAP as a health problem
  6. Questions for IAP-related symptoms/diseases: self-reported.


Ethics

All procedures were in accordance with the ethical standards of the Institutional Review Board and with the Helsinki declaration of 1975 that was revised in 2000. Ethical clearance was taken from the Institutional Ethics Committee of AIIHPH, Kolkata.

Statistics

All analyses were conducted with R software. Spearman's correlation coefficient was used to determine the association between IAP-related symptoms and sources of IAP and also with contributory factors to IAP. Univariate and multivariable logistic regression was done to find out the determinants of IAP sources and contributory factors and also to find their association with the IAP-related symptoms. Results were considered statistically significant at conventional P < 0.05 level.


   Results Top


The mean age of the study participants was 31.45 ± 7.3 years with 8.5 ± 3.8 mean years of schooling. About 71.7% were Hindus. Of the 120 households, 67.5% lived in households at ground floor. Among the study participants, 45% belonged to lower socioeconomic class (IV and V together). Of 120 households, 39 households had under-five children, out of these 39, 4 households had 2 under-five children each.

Out of 120, 60% households used kerosene as cooking fuel predominantly. Smoke from various sources was reported by the study participants out of which smoke from the neighboring houses troubled 57.5% of them. About 62.5% participants used smoke coils and burnt egg casings as mosquito repellants. More than 40% of houses had humid conditions in their houses. More than 60% of houses were overcrowded and more than 70% houses were poorly ventilated [Table 1].
Table 1: Distribution of households according to the parameters related to indoor air pollution (n=120)

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Five types of IAP sources and four contributory factors were reported in the study. Only 12 (10%) of the households had no sources of IAP. Majority of the households, i.e., 72 (60%) were found with three or more sources of IAP out of five as mentioned above. Only 24 (20%) houses were found to have no contributory factor with 40 (33.4%) households having three or more types contributory factors at the time of survey. Symptoms such as dizziness, eye irritation, and difficulty in breathing significantly correlated with the presence of IAP sources as well as its contributory factors.

There was a history of chronic respiratory diseases such as asthma, COPD in 36 households which significantly correlated with the presence of IAP sources and factors. The frequency of ARI per year was found to be highly correlated with a higher number of IAP sources and contributing factors to IAP [Table 2].
Table 2: Correlation of various respiratory symptoms/diseases among women and their under-five children with sources of indoor air pollution and contributing factors

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Among the study participants, 78 (65%) perceived IAP in their houses and 54 (45%) women perceived IAP as a major health problem. Out of these 54 women, 42 women took few measures to decrease it. Of these 42 women, 12 women took the cooking stove and cooked outside the house, in the passage and rest kept the door open most of the time.

Lower per capita income (PCI), those who lived on the ground floor and joint family were found to have higher odds of sources of IAP. Younger age of women, lower PCI and ground floor were found to be strongly associated with higher contributory factors of IAP [Table 3].
Table 3: Factors associated with sources and contributors of indoor air pollution: Univariate and Multivariable Logistic regression (n=120)

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Lower age and education of the women, higher PCI, living at ground floor, and higher numbers of IAP sources and contributing factors were found to have the presence of IAP related symptoms among the women. The odds of lower PCI and ground floor were attenuated after adjusting with all other variables [Table 4].
Table 4: Factors associated with presence of indoor air pollution-related symptoms: Univariate and Multivariable Logistic regression (n=120)

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   Discussion Top


The present study found that 90% of study households had at least one source of IAP.

It was found that 60% households in the slum used kerosene as primary fuel, but as per the DLHS-4 Kolkata, 78.4% urban population use clean fuel.[25] This difference may be attributed to lower PCI of our study participants which were living in the slum. Kerosene is an unclean fuel which produces a wide range of harmful pollutants including smoke. Kerosene being cheaper, the poor slum dwellers use it as their fuel.

No women were smoker and in 25% households, second-hand smoke (smoked by other members of the household) affected the women. More than half of the study participants reported that smoke from neighboring houses troubled them more. This is called “neighborhood effect.”[6]

Out of 120 households, 62.5% used IR (Insecticide Repellents) and a major chunk of households had IAP owing to smoke and dust from outside (vehicular exhausts). A similar study by Sarkar et al. in urban areas showed 90% used IR, but because ventilation was adequate, the IAP was nullified in the latter.[5]

Only 20% of households had no contributory factor to IAP. About 61.7% houses were overcrowded with 70% households with no cross ventilation. These findings are similar to a study done by Choi et al. in slum of Bengaluru.[19] Being in the slum area, the houses were all crowded together with common walls which left no space for windows. Many houses did not have well-defined rooms; single room acting as living room and kitchen. These findings demand an urgent need of intervention to protect the well-being of the slum dwellers by providing them well-designed houses. About 40% households had damp walls which could be the source of bio-aerosols such as microbial spores and fungi. Damp wall is usually a neglected feature but it could aid in acute respiratory infections especially in vulnerable under-five children.

Half of the respondents complained of irritation in the eyes which, as various studies suggested are common short-term health effects [5],[14] and 62.5% complained of difficulty in breathing while staying inside their houses. These people may be at risk of developing COPD or other airway diseases.

Eye irritation, difficulty in breathing, dry cough, and chronic respiratory diseases significantly correlated with number of sources as well as the contributory factors. These findings are similar to the study by Nandasena et al.[21]

About half of the women perceived IAP to be a major health problem, but due to economic constraints, they could not take definitive measures. About 80.8% women rightly perceived the presence of IAP in their homes which indicates that they are aware of IAP in their house but only 45% women perceived it as a major health problem. This gap must be filled. Forty-two women took some temporary remedial measures to counter the problem. Twelve (22.5%) women carried their cooking stove and cooked in the corridor, outside their house. Others tried to keep the door open, but not of much use. They mentioned that though they kept door open, vehicular smoke, and fumes from neighboring houses entered their houses.

IAP sources and contributory factors significantly correlated with recent and annual episodes of ARI among the under-five as suggested in previous studies by Wichmann and Voyi, Epstein et al. and Lakshmi et al. in India.[20],[26],[27]

The present study found that higher education was protective against sources of IAP and contributory factors. Well-educated women have better knowledge and are more aware. Lower PCI was found to have higher odds of having more IAP sources. Income is a prime determinant in choosing the fuel as liquefied petroleum gas (LPG) is costlier than kerosene which is used predominantly here though a new government scheme has been introduced by government named as Pradhan Mantri Ujjwala Yojana, but it has not covered this area of slum yet. The poor slum dwellers could not afford bigger houses with wider rooms. The households not living on the ground floor in the slum area reported that they perceived less IAP as they could open the windows and doors. The residents in the ground floor complained that on opening the windows the exhausts from the roads and garage polluted their houses. However, after adjusting with other socioeconomic factors the odds of living arrangement was attenuated.

The present study investigated the association of symptoms (IAP related) such as difficulty in breathing, and dry cough with the presence of IAP sources and contributory factors. On univariate analysis, the households with greater sources and factors had significant higher odds of having IAP-related symptoms. Furthermore, ground floor houses had more symptoms. However, after adjusting with all other socioeconomic factors, only the sources of IAP were found to be significant with 4.5 times odds. This indicates that sources are the main culprit in causing respiratory symptoms. The contributory factors though were associated but not significantly. Furthermore, women with higher education were associated with lower symptoms as they are more aware and careful.

Strength and limitations

The present study had some limitations. The presence of IAP was measured using a questionnaire and a checklist whereas the ideal measure of IAP is PM (Particulate Matter) 2.5 concentration.

Spirometry should have been done to assess the respiratory health. Since it was cross-sectional study, causation cannot be established. Some data were self-reported, so chances of recall bias are there.

The present study had its strength in its study setting, i.e., urban poor residing in slum. In India, slums are rapidly growing, but are often most resource-poor and the most neglected. The presence of IAP sources is accentuated by the poor housing and ill-ventilated housing conditions in slums. In addition, they use coal or kerosene fuel for cooking with no separate kitchen. Researchers have proved that in poorly ventilated dwellings, indoor smoke can be 100 times higher than acceptable levels for fine particles leading to inadvertent health problems.

Conclusion and Recommendations

The present study found that majority of the households used kerosene as fuel and smoke from neighboring houses, street enter their houses which lead to IAP. Major share of the households were overcrowded and ill-ventilated, accentuating the problem further. The various symptoms suffered by the women were found to be strongly associated with the number of sources of IAP in the house.

IAP and its detrimental effects are preventable. The urban poor living in slums should be provided with better housing conditions. The policy-makers should promote the use of clean fuel (LPG) as it is cost-effective and beneficial. The members of households who smoke indoors should be made aware and encouraged to quit smoking, at least indoors as it affects the health of their wives and children. Women should be educated and made aware of the deleterious effects of IAP on their own health and also of their children so that they can raise healthy children.

Acknowledgments

We would like to thank the officer in-charge and staff of RHUTC, Singur for their help and cooperation in conducting the study. We would also like to thank the health workers for helping us during our field visits.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
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  [Table 1], [Table 2], [Table 3], [Table 4]



 

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