Levels Of Indoor Air Pollution Research Articles

The effect of solid fuel use on childhood mortality in Nigeria: evidence from the 2013 cross-sectional household survey.

BackgroundIn Nigeria, approximately 69% of households use solid fuels as their primary source of domestic energy for cooking. These fuels produce high levels of indoor air pollution. This study aimed to determine whether Nigerian children residing in households using solid fuels at <5 years of age were at higher risk of death.MethodsThe 2013 Nigeria Demographic and Health Survey data were analysed in Cox regression analyses to examine the effects of solid fuel use on deaths of children aged 0–28 days (neonatal), 1–11 months (post-neonatal), and 12–59 months (child).ResultsThe results indicated that approximately 0.8% of neonatal deaths, 42.9% of post-neonatal deaths, and 36.3% of child deaths could be attributed to use of solid fuels. The multivariable analyses found that use of solid fuel was associated with post-neonatal mortality (hazard ratio [HR] =1.92, 95% confidence interval [CI]: 1.42–2.58) and child mortality (HR = 1.63, CI: 1.09–2.42), but was not associated with neonatal mortality (HR = 1.01, CI: 0.73–1.26). Living in rural areas and poor households were associated with an increased risk of death during the three mortality periods.ConclusionLiving in a rural area and poor households were strongly associated with an increased risk of a child > 1 to < 60 months dying due to use of solid fuels. The health effects of household use of solid fuels are a major public health threat that requires increased research and policy development efforts. Research should focus on populations in rural areas and low socioeconomic households so that child survival in Nigeria can be improved.

Taking into Account Space-Time Activity and Indoor Air Levels in the Estimation of Exposure to Atmospheric Pollutants during Pregnancy: Does It Make a Difference?

Background: Epidemiological studies have suggested adverse affects of atmospheric pollutants on birth outcomes. In most studies, exposure assessment did not consider space-time activity or indoor air pollution levels. Objectives: Our objective was to compare different approaches allowing to characterize atmospheric pollution exposure during pregnancy. A secondary aim was to quantify the impact of the cleaning of the GPS data used to assess space-time activity. Methods: We recruited 40 pregnant women living in an urban area and had them carry a GPS during one week at each trimester of pregnancy; indoor levels of fine particulate matter (PM2.5) were measured in the homes of 10 women. Outdoor air pollutants concentrations were estimated from a dispersion model with a high spatial resolution (10x10 meters grid) and were corrected for seasonal variations. We compared trimester- specific exposure levels of the women assessed only from outdoor air pollutants levels at the home address (Model 1) with approaches incorporating space-time activity (raw GPS data: Model 2, clean GPS data: Model 3) and with a model incorporating indoor PM2.5 levels when the woman was home (Model 4). Results: Considering only outdoor air pollutants levels, the exposure model taking into account space-time activity with clean GPS data (Model 3) was more strongly correlated with the model estimating the levels of air pollutants at the home address (Model 1, r=0.85) than with the model taking into account space-time activity with raw GPS data (Model 2, r=0.73). Each of these models based on outdoor air pollutants levels (Models 1, 2 and 3) were moderately correlated (r=0.4-0.5) with the clean GPS data model incorporating PM2.5 indoor measures when the woman was home (Model 4). Conclusion: GPS data require cleaning as classical GPS often lose their signal indoors. In this urban area, a purely outdoor model had a moderate correlation with an exposure estimate incorporating indoor levels.

NO2, SO2 and O3 Indoor-Outdoor Relationships at Schools in Ekurhuleni Metropolitan Municipality, Gauteng Province, South Africa

Introduction: The relationship between indoor and outdoor air pollution levels is important for the understanding of the health effects of outdoor air pollution. Children spend approximately six to...

Aerosol distribution during open suctioning and long-term surveillance of air quality in a respiratory care center within a medical center.

The investigation of hospital air quality has been conducted in wards, ICUs, operating theaters, and public areas. Few studies have assessed air quality in respiratory care centers (RCCs), especially in mechanically ventilated patients with open suctioning. The RCC air quality indices (temperature, relative humidity, levels of CO2, total volatile organic compounds, particulate matter [PM], bacteria, and fungi) were monitored over 1 y. The air around the patient's head was sampled during open suctioning to examine the probability of bioaerosol exposure affecting health-care workers. This investigation found that the levels of indoor air pollutants (CO2, PM, bacteria, and fungi) were below the indoor air quality standard set by the Taiwan Environmental Protection Agency. Meanwhile, the levels of total volatile organic compounds sometimes exceeded the indoor air quality standard, particularly in August. The identified bacterial genera included Micrococcus species, Corynebacterium species, and Staphylococcus species, and the predominant fungal genera included yeast, Aspergillus species, Scopulariopsis species, and Trichoderma species. Additionally, airborne PM2.5, PM1, and bacteria were clearly raised during open suctioning in mechanically ventilated patients. This phenomenon demonstrated that open suctioning may increase the bacterial exposure risk of health-care workers. RCC air quality deserves long-term monitoring and evaluation. Health-care workers must implement self-protection strategies during open suctioning to ensure their occupational health and safety in health-care settings.

Air quality in New York City hookah bars

BackgroundHookahs are increasingly being used in the USA and elsewhere. Despite the popularity of hookah bars, there is a paucity of research assessing the health effects of hookah smoke, and...

Investigation of time-resolved atmospheric conditions and indoor/outdoor particulate matter concentrations in homes with gas and biomass cook stoves in Nogales, Sonora, Mexico

This paper reports findings from a case study designed to investigate indoor and outdoor air quality in homes near the United States–Mexico border. During the field study, size-resolved continuous particulate matter (PM) concentrations were measured in six homes, while outdoor PM was simultaneously monitored at the same location in Nogales, Sonora, Mexico, during March 14–30, 2009. The purpose of the experiment was to compare PM in homes using different fuels for cooking, gas versus biomass, and to obtain a spatial distribution of outdoor PM in a region where local sources vary significantly (e.g., highway, border crossing, unpaved roads, industry). Continuous PM data were collected every 6 seconds using a valve switching system to sample indoor and outdoor air at each home location. This paper presents the indoor PM data from each home, including the relationship between indoor and outdoor PM. The meteorological conditions associated with elevated ambient PM events in the region are also discussed. Results indicate that indoor air pollution has a strong dependence on cooking fuel, with gas stoves having hourly averaged median PM3 concentrations in the range of 134 to 157 μg m−3 and biomass stoves 163 to 504 μg m−3. Outdoor PM also indicates a large spatial heterogeneity due to the presence of microscale sources and meteorological influences (median PM3: 130 to 770 μg m−3). The former is evident in the median and range of daytime PM values (median PM3: 250 μg m−3, maximum: 9411 μg m−3), while the meteorological influences appear to be dominant during nighttime periods (median PM3: 251 μg m−3, maximum: 10,846 μg m−3). The atmospheric stability is quantified for three nighttime temperature inversion episodes, which were associated with an order of magnitude increase in PM10 at the regulatory monitor in Nogales, AZ (maximum increase: 12 to 474 μg m−3).Implications:Regulatory air quality standards are based on outdoor ambient air measurements. However, a large fraction of time is typically spent indoors where a variety of activities including cooking, heating, tobacco smoking, and cleaning can lead to elevated PM concentrations. This study investigates the influence of meteorology, outdoor PM, and indoor activities on indoor air pollution (IAP) levels in the United States–Mexico border region. Results indicate that cooking fuel type and meteorology greatly influence the IAP in homes, with biomass fuel use causing the largest increase in PM concentration.

Relationship between indoor air pollutant levels and residential environment in children with atopic dermatitis.

PurposeThis study was aimed to investigate the relationship between indoor air pollutant levels and residential environment in children with atopic dermatitis (AD) living in Seoul.MethodsA total of 150 children with AD were included. Residential environment was assessed by questionnaires which were completed by their parents. To evaluate the level of exposure to the indoor air pollutants, concentrations of the indoor air pollutants including particulate matter with diameter less than 10 µm (PM10), formaldehyde, carbon dioxide (CO2), carbon monoxide (CO), nitrogen dioxide (NO2), Total Volatile Organic Compound (TVOC), benzene, toluene, ethyl-benzene, xylene, styrene, bacterial aerosols, and airborne fungi were measured.ResultsA significant difference was exhibited in the levels of PM10 in case of visible fungus on the walls (P=0.047). There was relationship between the construction year of the house, moving to a newly constructed building within 1 year and formaldehyde level. With the use of artificial air freshener, the differences were found in the concentrations of TVOC (P=0.003), benzene (P=0.015), toluene (P=0.012) and ethyl-benzene (P=0.027). The concentration of xylene was significantly high when oil was used as heating fuel (P=0.015). Styrene exhibited differences depending on building type and its concentrations were significantly high in a residential and commercial complex building (P=0.005). The indoor concentration of bacterial aerosols was significantly low with the use of air cleaner (P=0.045). High NO2, benzene concentrations were present in case of almost no ventilation (P=0.028 and P=0.028, respectively).ConclusionsIndividual residential environments are closely related with the levels of the indoor air pollutants. To alleviate AD symptoms, simple questions about residential environments such as visible fungus on the walls and the use of artificial air freshener are helpful to assess the possibility of increased indoor air pollutant levels when direct measurement is not available.

Is ambient air pollution another risk factor of tuberculosis?

Is ambient air pollution another risk factor of tuberculosis?

Emission Characteristics of Particulate Matter and Volatile Organic Compounds in Cow Dung Combustion

Biomass fuel is used for cooking and heating, especially in developing countries. Combustion of biomass fuel can generate high levels of indoor air pollutants, including particulate matter (PM) and volatile organic compounds (VOCs). This study characterized PM and VOC emissions from cow dung combustion in a controlled experiment. Dung from grass-fed cows was dried and combusted using a dual-cone calorimeter. Heat fluxes of 10, 25, and 50 kW/m(2) were applied. The concentrations of PM and VOCs were determined using a dust spectrometer and gas chromatography/mass spectrometry, respectively. PM and VOC emission factors were much higher for the lower heat flux, implying a fire ignition stage. When the heat flux was 50 kW/m(2), the CO2 emission factor was highest and the PM and VOC emission factors were lowest. Particle concentrations were highest in the 0.23-0.3 μm size range at heat fluxes of 25 and 50 kW/m(2). Various toxic VOCs, including acetone, methyl ethyl ketone, benzene, and toluene, were detected at high concentrations. Although PM and VOC emission factors at 50 kW/m(2) were lower, they were high enough to cause extremely high indoor air pollution. The characteristics of PM and VOC emissions from cow dung combustion indicated potential health effects of indoor air pollution in developing countries.

Characteristics of indoor air pollution in rural mountainous and rural coastal communities in Indonesia

The increased use of biomass fuel use among rural Indonesian households for years despite national program on subsidized LPG fuel distribution pose threat of indoor air pollution for the householders. Indoor air pollution levels of PM2.5 and CO in the kitchen of 40 households using the fuelwood as the main cooking fuel were measured in the same season in mountainous and coastal areas in Indonesia. The temporal variations of PM2.5 and its size distributions were simultaneously measured using photoelectric UCB monitor and personal cascade impactor, respectively. While carbon monoxide (CO) concentrations were measured using USB-CO monitors. Household indoor air pollution in the mountainous area was generally higher than that in the coastal area. This is because the households in coastal area have higher kitchen volume (about three times), smaller ventilation area (about 1.7 times) and shorter cooking duration with wood fuel (0.6 times) than those in mountainous area. Yet, during cooking with fuelwood, the indoor PM2.5 concentrations at the cook site showed almost comparable results for both sites. The wood stove burning in coastal area tended to be in flaming combustion than in mountainous area. This can be indicated by a higher fraction of finest particles in PM2.5, a higher fraction of EC in PM2.5 and a higher fraction of K+ and Cl− ions in PM2.5 mass concentrations. The time-averaged CO concentrations for 22-h measurements at the mountainous area were higher than those in coastal area. The mountainous area showed higher positive correlation relationship between the measured concentrations of CO and PM2.5 than those in the coastal area. The use of cleaner fuel, e.g., subsidized LPG fuel in rural area should be promoted and managed intensively in mountainous area than in coastal area to avoid people exposure of health damaging indoor air pollutants.

Evaluation of indoor air quality in a museum (Bait Al Zubair) and residential homes

This study was conducted with an aim to know the extent to which artefacts displayed in a museum could be affected due to raised levels of indoor air pollutants. The other objective of this work was to identify whether the quality of air in the residential homes is acceptable for the residents or not. In order to fulfil these objectives, the levels of air quality parameters were recorded at various locations of the museum and residential homes. The determined values of these parameters were compared with the permitted values defined in international standards/guidelines. Results showed that the levels of nitrogen dioxide, relative humidity and temperature in the museum were within the allowable limits while that of ozone, sulphur dioxide and total particulate matters were above the thresholds, which could cause damage to the exhibits in the museum. Furthermore, the results obtained from the residential homes indicated that the elevated levels of carbon dioxide, total volatile organic compounds and temperature in the indoor environment of these homes could cause unhealthy effects to the residents.

INDOOR AIR QUALITY AND PREVALENCE OF SICK BUILDING SYNDROME AMONG OFFICE WORKERS IN TWO DIFFERENT OFFICES IN SELANGOR

This study was done to investigate the relationship between Indoor Air Quality (IAQ) and prevalence of Sick Building Syndrome (SBS) in two different offic es (old and new) in Selangor. Hundred and seventy workers were selected consist of 85 office workers for each building. Questionnaire based on Indoor Ai r Quality and Work Symptoms Survey, NIOSH, Indoor Environmental Quality Survey, 1991 was used to record prevalence of SBS. Measurement of indoor air quality was performed using instruments recommended by IAQ Code of Practice, Department of Occupational Safety and Health, Malaysia. IAQ supplied air was significantly higher in new buildi ng with the median 22.49 cfm/person while 15.79 cfm/person in old building (z = -6.23, p<0.001). Th e prevalence of SBS in old building was significant ly higher compared to the new building ( χ 2 = 30.6, p<0.001). Levels of indoor air pollutants i n old building were significantly higher compared to new building for: CO 2 (z = -4.62, p<0.001); TVOC (z = -2.71, p<0.05); PM 10 (z = -2.11, p<0.05); PM 2.5 (z = -2.35, p<0.05), meanwhile for UFP (z = 4.72, p<0.001) and THI value (z = -4.57, p<0.001), new building was si gnificantly higher compared to old building. There was significant association between the prevalence of S BS and the indoor air pollutants in the old buildin g namely CO 2 (OR = 3.56, 95% CI = 1.327-9.548); CO (OR = 4.95, 95% CI = 1.740-14.127); TVOC (OR = 4.71, 95% CI = 1.571-14.151); PM 10 (OR = 6.23, 95% CI = 2.278-17.065) and PM 2.5 (OR = 4.18, 95% CI = 1.564-11.199), while in the new building, the preva lence of SBS showed significant association with an indoor air pollutant namely UFP (OR = 6.53, 95% CI = 1.757-24.327). After controlling the cofounders; age, medical condition, smoking and having pet at h ome, the results showed that CO 2, CO, TVOC, PM 10 , PM 2.5 influenced SBS in old building while UFP influence d SBS in the new building. This study suggested that when there was an increase in the ventilation rates per person in office building, it would signi ficantly reduced prevalence of SBS, even though both buildings meet the existing ASHRAE ventilation standards for office building. Reduction in prevalence of SBS would depend on the increase in ventilation rates, ventilation effectiveness and reduction in indoor a ir pollutants that can cause SBS.

Higher prevalence of breathlessness in elderly exposed to indoor aldehydes and VOCs in a representative sample of French dwellings

The purpose of this study was to explore respiratory health effects of indoor exposures to aldehydes and volatile organic compounds (VOCs) in elderly living in a population-based representative sample of French dwellings and to compare them to the rest of the occupants of the dwellings. Twenty VOCs were objectively measured in 490 main dwellings. The respiratory conditions were assessed through a standardized questionnaire in 1012 inhabitants aged over 15 years, 144 of whom were aged over 65 years. Generalized estimating equations (GEE) were used to model the relationship between respiratory health outcomes and air pollutants concentrations using the median value of the distribution to define elevated exposure. Similar levels of indoor air pollutants were found in elderly and others. However, associations between breathlessness and living in dwellings with elevated concentrations of toluene and o-xylene respectively were statistically significant in elderly but not in the rest of the population (adjusted odds ratios (AOR(95% confidence interval)=3.36(1.13, 9.98) and 2.85(1.06, 7.68) in elderly vs. 0.91(0.59, 1.39) and 0.79( 0.47, 1.34) in the others respectively). A more pronounced effect of n-decane on past year breathlessness was observed in case of poor ventilation in the dwellings. Our results showed a higher risk of breathlessness in elderly exposed to indoor air pollution than in the rest of the exposed population. Further investigations are needed to confirm whether this is related to frailty in elderly.

Change in secondhand smoke levels in a public hospital in Budapest following anti-smoking policy implementation in 2011

Our previous 2009 study demonstrated high secondhand smoke levels throughout a public hospital in Budapest. To compare changes in indoor air pollution level between 2009 and 2012, before and after the Hungarian anti-smoking policy legislation adopted in 2011. TSI SidePak AM510 Personal Aerosol Monitor was used. In-patient care department PM2.5 levels declined by 92% from 87.7 μg/m3 to 6.9 μg/m3. Non-patient care area PM2.5 level increased by 67% from 64.8 μg/m3 to 108.0 μg/m3. The increase was driven entirely by a large increase in the level in public toilets. Excluding these, there was a 83% drop in PM2.5 in non-patient care areas from 64.8 μg/m3 to 11.1 μg/m3. PM2.5 decreased significantly due to the 2011 law. However, smoking still occurred in the hospital, albeit in less frequently visited areas. A stricter enforcement of this beneficial law is needed to reach a comprehensive smoke-free hospital environment.

Exploring the consequences of climate change for indoor air quality**Reprinted with permission from Climate Change, the Indoor Environment, and Health (2011) by the National Academy of Sciences, Courtesy of the National Academies Press, Washington, DC.

Climate change will affect the concentrations of air pollutants in buildings. The resulting shifts in human exposure may influence public health. Changes can be anticipated because of altered outdoor pollution and also owing to changes in buildings effected in response to changing climate. Three classes of factors govern indoor pollutant levels in occupied spaces: (a) properties of pollutants; (b) building factors, such as the ventilation rate; and (c) occupant behavior. Diversity of indoor conditions influences the public health significance of climate change. Potentially vulnerable subpopulations include not only the young and the infirm but also those who lack resources to respond effectively to changing conditions. Indoor air pollutant levels reflect the sum of contributions from indoor sources and from outdoor pollutants that enter with ventilation air. Pollutant classes with important indoor sources include the byproducts of combustion, radon, and volatile and semivolatile organic compounds. Outdoor pollutants of special concern include particulate matter and ozone. To ensure good indoor air quality it is important first to avoid high indoor emission rates for all pollutants and second to ensure adequate ventilation. A third factor is the use of air filtration or air cleaning to achieve further improvements where warranted.

Indoor air quality in the rural India

PurposeThe purpose of this paper is to assess the exposure of cooks in rural India (55 households) to the indoor air pollution levels emitted from burning of different fuels, i.e. cow dung, wood, liquefied petroleum gas (LPG) and propane natural gas(PNG) kerosene for cooking purposes.Design/methodology/approachIndoor air quality was monitored during cooking hours in 55 rural households to estimate the emissions of PM10, PM2.5, CO, NO2, VOCs and polyaromatic hydrocarbons (PAHs). While, PM10 and PM2.5 were monitored using personal dust samplers on quartz filter paper, CO and VOCs were monitored using on line monitors. The PM10 and PM2.5 mass collected on filter papers was processed to analyse the presence of PAHs using GC.FindingsResults revealed that cow dung is the most polluting fuel with maximum emissions of PM10, PM 2.5, VOCs, CO, NO2 and Benzene followed by wood and kerosene. Interestingly kerosene combustion emits the highest amount of PAHs. Emissions for all the fuels show the presence of carcinogenic PAHs which could be a serious health concern. The composition of LPG/PNG leads to reductions of pollutants because of better combustion process. LPG which is largely propane and butane, and PNG which is 90 per cent methane prove to be healthier fuels. Based on the results, the authors suggest that technological intervention is required to replace the traditional stoves with improved fuel efficient stoves.Practical implicationsThe prevailing weather condition and design of the kitchen in these rural houses severely affect the concentration of pollutants in the kitchen as winter season combined with inadequate ventilation leads to reduced dispersion and accumulation of air pollutants in small kitchens.Originality/valueThe present study provides a detailed analysis of impact of widely‐used cooking practices in India. Even today, countries such as India rely on biomass for cooking practices exposing the cooks to high level of carcinogenic pollutants. Further, women and girls are the most threatened group as they are the primary cooks in these rural Indian settings. Based on the results, the authors suggest that technological as well as policy intervention is required to replace the traditional stoves with improved fuel efficient stoves.

Potential of Biomass Conservation Through Dissemination of Efficient Cook Stoves in Pakistan

Majority of the rural population of Pakistan meet their domestic cooking and heating energy needs by burning biomass in inefficient traditional cook stoves (TCS) resulting in deforestation and indoor air pollution (IAP). High exposures to indoor air pollutants have resulted in serious health problems. In the last few decades, scientific methods have been applied for improving the performance of cook stoves and various types of improved cook stoves (ICS) have been introduced and disseminated in rural areas of the developing countries. This paper presents an assessment of the potential of ICS for biomass conservation in Pakistan. The total potential of biomass saving through replacement of all TCS with ICS has been estimated as 14.5 million tonnes. The paper concludes that more than half of the total biomass consumption for cooking and heating purposes could be saved through substitution of TCS with ICS. The dissemination of ICS would also result in the conservation of forests, reduction in the indoor air pollution level and associated health hazards etc.

Indoor Air Pollution and Children's Health: Net Benefits from Stove and Behavioral Interventions in Rural China

Indoor air pollution (IAP) from cooking and heating stoves is a major cause of acute respiratory infections (ARI) and a serious health risk in developing countries. This paper examines improvements in respiratory health for children five and under in rural China resulting from stove and behavioural interventions to reduce IAP. The analysis uses data from a World Bank/Government of China project completed in 2006, whereby a large number of rural households from four provinces in China were subject to different combinations of stove improvement and behavioural interventions to reduce IAP levels and exposure. Difference-in-difference and matching models show that both stove and behavioural interventions were effective in reducing the incidence of ARI, although the latter are more cost effective.

Personal, indoor and outdoor air pollution levels among pregnant women

AimThe aims of this study were to investigate the relationship between pregnant women's personal exposures to NOx, NO2, PM2.5 concentration and absorbance as a marker for black carbon and their indoor and outdoor concentration levels at their residence, and also to identify predictors of personal exposure and indoor levels using questionnaire and time activity data. MethodWe recruited 54 pregnant women in Barcelona who carried a personal PM2.5 sampler for two days and NOx/NO2 passive badges for one week, while indoor and outdoor PM2.5 and NOx/NO2 levels at their residence were simultaneously measured. Time activity and house characteristics were recorded. Gravimetry determinations for PM2.5 concentration and absorbance measurements were carried out on the PM2.5 filter samples. ResultsLevels of personal exposure to NOx, PM2.5 and absorbance were slightly higher than indoor and outdoor levels (geometric mean of personal NOx = 61.9 vs indoor NOx = 60.6 μg m−3), while for NO2 the indoor levels were slightly higher than the personal ones. Generally, there was a high statistically significant correlation between personal exposure and indoor levels (Spearman's r between 0.78 and 0.84). Women spent more than 60% of their time indoors at home. Ventilation of the house by opening the windows, the time spent cooking and indicators for traffic intensity were re-occurring statistically significant determinants of the personal and indoor pollutants levels with models for NOx explaining the 55% and 60% of the variability respectively, and models for NO2 explaining the 39% and 16% of the variability respectively. Models for PM2.5 and absorbance explained the least of the variability. ConclusionOur findings improve the current understanding of the characterization and inter-associations between personal, indoor and outdoor pollution levels among pregnant women. Variability in personal and indoor NOx and to a lesser extent NO2 levels could be explained well, but not the variability in PM2.5 could be explained.

Exposure of population from residential radon: a case study for district Hattian, Azad Kashmir, Sub-Himalayas, Pakistan

Indoor air quality has acquired considerable importance in recent years. Tighter buildings with poorer ventilation systems have led towards higher levels of indoor air pollution. Radon is considered to be most significant perilous gas among the various air contaminants found in the residential environment. To determine the risk posed by residential radon exposure, a survey was carried out in the Hattian district of the state of Azad Jammu and Kashmir, Pakistan. In this context, 160 houses were carefully selected for the installation of CR-39-based National Radiological Protection Board-type detectors installation. After exposing the CR-39 detectors for a period of 90 d, they were etched in 6 M chemical solution of sodium hydroxide at a temperature of 80°C for a period of 16 h. The detectors were read under an optical microscope and observed track densities were converted into the indoor radon concentration using a calibration factor of 2.7 tracks cm(-2) h(-1) per kBqm(-3). For the current study, observed radon concentrations ranged from 35 to 175 Bqm(-3), whereas the mean annual effective radon doses received by the inhabitants of the area ranged from 0.88 ± 0.12 to 4.41 ± 0.20 mSv with an average value of 2.62 ± 0.12 mSv. These reported values are less than the limits (standards) recommended by the different world organisations.