Levels Of Indoor Air Pollution Research Articles

Impact of indoor air pollution on DNA damage and chromosome stability: a systematic review.

Indoor air pollution is becoming a rising public health problem and is largely resulting from the burning of solid fuels and heating in households. Burning these fuels produces harmful compounds, such as particulate matter regarded as a major health risk, particularly affecting the onset and exacerbation of respiratory diseases. As exposure to polluted indoor air can cause DNA damage including DNA sd breaks as well as chromosomal damage, in this paper, we aim to provide an overview of the impact of indoor air pollution on DNA damage and genome stability by reviewing the scientific papers that have used the comet, micronucleus, and γ-H2AX assays. These methods are valuable tools in human biomonitoring and for studying the mechanisms of action of various pollutants, and are readily used for the assessment of primary DNA damage and genome instability induced by air pollutants by measuring different aspects of DNA and chromosomal damage. Based on our search, in selected studies (in vitro, animal models, and human biomonitoring), we found generally higher levels of DNA strand breaks and chromosomal damage due to indoor air pollutants compared to matched control or unexposed groups. In summary, our systematic review reveals the importance of the comet, micronucleus, and γ-H2AX assays as sensitive tools for the evaluation of DNA and genome damaging potential of different indoor air pollutants. Additionally, research in this particular direction is warranted since little is still known about the level of indoor air pollution in households or public buildings and its impact on genetic material. Future studies should focus on research investigating the possible impact of indoor air pollutants in complex mixtures on the genome and relate pollutants to possible health outcomes.

Indoor air quality prediction modeling for a naturally ventilated fitness building using RNN-LSTM artificial neural networks

PurposeExposure to indoor air pollutants poses a significant health risk, contributing to various ailments such as respiratory and cardiovascular diseases. These unhealthy consequences are specifically alarming for athletes during exercise due to their higher respiratory rate. Therefore, studying, predicting and curtailing exposure to indoor air contaminants during athletic activities is essential for fitness facilities. The objective of this study is to develop a neural network model designed for predicting optimal (in terms of health) occupancy intervals using monitored indoor air quality (IAQ) data.Design/methodology/approachThis research study presents an innovative approach employing a long short-term memory (LSTM) recurrent neural network (RNN) to determine optimal occupancy intervals for ensuring the safety and well-being of occupants. The dataset was collected over a 3-month monitoring campaign, encompassing 15 meteorological and indoor environmental parameters monitored. All the parameters were monitored in 5-min intervals, resulting in a total of 77,520 data points. The dataset collection parameters included the building’s ventilation methods as well as the level of occupancy. Initial preprocessing involved computing the correlation matrix and identifying highly correlated variables to serve as inputs for the LSTM network model.FindingsThe findings underscore the efficacy of the proposed artificial intelligence model in forecasting indoor conditions, yielding highly specific predicted time slots. Using the training dataset and established threshold values, the model effectively identifies benign periods for occupancy. Validation of the predicted time slots is conducted utilizing features chosen from the correlation matrix and their corresponding standard ranges. Essentially, this process determines the ratio of recommended to non-recommended timing intervals.Originality/valueHumans do not have the capacity to process this data and make such a relevant decision, though the complexity of the parameters of IAQ imposes significant barriers to human decision-making, artificial intelligence and machine learning systems, which are different. Present research utilizing multilayer perceptron (MLP) and LSTM algorithms for evaluating indoor air pollution levels lacks the capability to predict specific time slots. This study aims to fill this gap in evaluation methodologies. Therefore, the utilized LSTM-RNN model can provide a day-ahead prediction of indoor air pollutants, making its competency far beyond the human being’s and regular sensors' capacities.

Analysis of air quality and ventilation systems in production working areas of PT. A

PT. A is a manufacturing industry specializing in plastic-based cosmetic packaging. The work area of blow molding and injection molding 1 & 2 is the center of the company's main activity, involving many employees with diverse roles. The high density of work activity and heat-generating machines pose significant challenges to the workspace temperature, impacting worker health and well-being. Indoor air pollution levels, 2 to 10 times higher than outside, raise serious concerns, given people's prolonged indoor exposure. Poor air quality can lead to discomfort, health issues, and work accidents, affecting company operations and customer confidence. Three production units of PT. A were analyzed, focusing on air quality and ventilation systems. Primary data collection involved observations and interviews with four company informants regarding the ventilation system. Secondary data included direct measurements of air pollutants, dust particles, and environmental conditions by designated third parties. PT. A has implemented multiple mechanical ventilation systems to enhance airflow within the production area. Although the air quality in the blow molding and injection molding 1&2 workspaces meets the standards of the Minister of Manpower of the Republic of Indonesia No. 5 of 2018, the working climate in these three production areas exceeds the specified thresholds. Engineering interventions are recommended to address this issue and improve worker safety, health, comfort, and productivity without long-term consequences.

Development and Performance Evaluation of Biomass-Based Injera Baking Gasifier Stove: A Case Study of Clean Cooking Technologies in Ethiopia.

The primary energy source in Ethiopia is biomass. Over 80% of Ethiopians are rural dwellers who rely on biomass energy for lighting and cooking. In most parts of Ethiopia, injera is traditionally baked using an open fire, a three stone, or a device using woody biomass. These baking stoves have very low efficiency and consume a significant amount of fuel. Moreover, these traditional baking stoves have released large amounts of indoor air pollution, which has led to different types of health-related risks, especially for women and children in the country. Therefore, the aim of this study was to investigate efficient and fuel-saving injera baking technologies. Rigorously, an injera baking gasifier stove was designed, developed, and characterized in detail through water boiling and control cooking test methods. The indoor air pollution level was evaluated using particulate matter measuring instruments. The result indicated that the developed gasifier stove had a thermal efficiency of 21.8%. Furthermore, an 86% fuel savings performance was demonstrated by the controlled cooking test for the injera baking gasifier stove. The average emission concentrations of particulate matter and carbon monoxide were 608 µg/m3 and 9 ppm, respectively, during indoor air pollution determination. The study showed that injera baking gasifier stoves are a promising cooking technology for societies where baking is mostly dependent on traditional biomass fuel.

Household air pollution and attributable burden of disease in rural China: A literature review and a modelling study

Household air pollution prevails in rural residences across China, yet a comprehensive nationwide comprehending of pollution levels and the attributable disease burdens remains lacking. This study conducted a systematic review focusing on elucidating the indoor concentrations of prevalent household air pollutants—specifically, PM2.5, PAHs, CO, SO2, and formaldehyde—in rural Chinese households. Subsequently, the premature deaths and economic losses attributable to household air pollution among the rural population of China were quantified through dose-response relationships and the value of statistical life. The findings reveal that rural indoor air pollution levels frequently exceed China's national standards, exhibiting notable spatial disparities. The estimated annual premature mortality attributable to household air pollution in rural China amounts to 966 thousand (95% CI: 714–1226) deaths between 2000 and 2022, representing approximately 22.2% (95% CI: 16.4%−28.1%) of total mortality among rural Chinese residents. Furthermore, the economic toll associated with these premature deaths is estimated at 486 billion CNY (95% CI: 358–616) per annum, constituting 0.92% (95% CI: 0.68%−1.16%) of China's GDP. The findings quantitatively demonstrate the substantial disease burden attributable to household air pollution in rural China, which highlights the pressing imperative for targeted, region-specific interventions to ameliorate this pressing public health concern.

Nexus of Gender and Renewable Energy: Importance and Trends in Global and National context

This is an article on “Nexus of Gender and Renewable Energy: Importance and Trends in Global and National context”. Here, as per objectives of the study, literatures on the respective issues have been reviewed by a desk review process. This paper has highlighted the issues on importance and trends of gender-energy nexus. The reviews have tried to show association between SDG 7: "Ensure access to affordable, reliable, sustainable and modern energy for all.” SDG: 5 is "Achieve gender equality and empower all women and girls" for sustainable development. The major highlight of the paper is effective Policy implication, participation, importance and trends, poverty and energy justice and transitions are inseparable entities of gender energy nexus. Energy access saves time, reduces drudgery, reduces indoor air pollution levels, improves education and improves health of women, alleviates poverty etc. Energy access creates new opportunities for income generating activities.

Indoor particulate matter concentrations and air cleaner intervention association with biomarkers in former smokers with COPD

BackgroundIndoor pollutants have been associated with worse clinical outcomes in chronic obstructive pulmonary disease (COPD). Elevated biomarkers are associated with ambient pollution exposure, however the association with indoor pollution remains unclear. MethodsFormer smokers with spirometry-confirmed COPD were randomized to portable air cleaner or placebo. Indoor particulate matter (PM2.5, PM10, and ultrafine particles [UFP; PM<0.1]) and biomarkers were measured longitudinally at pre-specified intervals and course PM fraction (PM10-2.5) was calculated. Biomarkers were categorized based on associations with biologic mechanisms: inflammation (white blood cell count, interleukin [IL]-6, IL-8, IL-1β, tumor necrosis factor-α, interferon-γ, serum amyloid A), platelet activation (P-selectin, CD40 ligand [CD40L], 11-dehdydro-thromboxane-B2 [11dTxB2]), endothelial dysfunction (Vascular Cell Adhesion Molecule [VCAM]-1, Intercellular Adhesion Molecule [ICAM]-1), and oxidative stress (thiobarbituric acid reactive substances [TBARS], 8-hydroxydeoxyguanosine, 8-isoprostane). Associations between PM concentrations and each biomarker were analyzed using multivariable linear mixed models. An intention-to-treat analysis was performed to evaluate the air cleaner intervention on the biomarker levels longitudinally. ResultsFifty-eight participants were randomized to each group. Finer PM was more strongly associated with higher IL-8 (mean difference per doubling: UFP 13.9% [p = 0.02], PM2.5 6.8% [p = 0.002], PM10-2.5 5.0% [p = 0.02]) while interferon-γ was associated with UFP and IL-1β with PM10-2.5. UFP and PM2.5 were associated with elevated levels of the oxidative stress biomarkers TBARS and 8-isoprostane respectively. For platelet activation markers, UFP was associated with higher 11dTxB2 while PM2.5 was associated with higher P-selectin and CD40L. Pollutants were not associated with biomarkers of endothelial dysfunction. In intention-to-treat analysis there was no association of the air cleaner intervention with any of the biomarkers. DiscussionAmong former smokers with COPD, elevated levels of indoor air pollutants, particularly ultrafine particles (PM<0.1), were associated with elevated biomarkers of inflammation, platelet activation, and oxidative stress. However, an air cleaner intervention that reduced PM did not significantly reduce biomarker levels.

Analysis of inequalities in personal exposure to PM2.5: A modelling study for the Greater London school-aged population

Exposure to air pollution can lead to negative health impacts, with children highly susceptible due to their immature immune and lung systems. Childhood exposure may vary by socio-economic status (SES) due to differences in both outdoor and indoor air pollution levels, the latter of which depends on, for example, building quality, overcrowding and occupant behaviours; however, exposure estimates typically rely on the outdoor component only. Quantifying population exposure across SES requires accounting for variations in time-activity patterns, outdoor air pollution concentrations, and concentrations in indoor microenvironments that account for pollution-generating occupant behaviours and building characteristics. Here, we present a model that estimates personal exposure to PM2.5 for ~1.3 million children aged 4–16 years old in the Greater London region from different income groups. The model combines 1) A national time-activity database, which gives the percentage of each group in different residential and non-residential microenvironments throughout a typical day; 2) Distributions of modelled outdoor PM2.5 concentrations; 3) Detailed estimates of domestic indoor concentrations for different housing and occupant typologies from the building physics model, EnergyPlus, and; 4) Non-domestic concentrations derived from a mass-balance approach. The results show differences in personal exposure across socio-economic groups for children, where the median daily exposure across all scenarios (winter/summer and weekends/weekdays) is 17.2 μg/m3 (95%CIs: 12.1 μg/m3–41.2 μg/m3) for children from households in the lowest income quintile versus 14.5 μg/m3 (95%CIs: 11.5 μg/m3 – 27.9 μg/m3) for those in the highest income quintile. Though those from lower-income homes generally fare worse, approximately 57 % of London's school-aged population across all income groups, equivalent to 761,976 children, have a median daily exposure which exceeds guideline 24-h limits set by the World Health Organisation. The findings suggest residential indoor sources of PM2.5 are a large contributor to personal exposure for school children in London. Interventions to reduce indoor exposure in the home (for example, via the maintenance of kitchen extract ventilation and transition to cleaner cooking fuels) should therefore be prioritised along with the continued mitigation of outdoor sources in Greater London.

Exposure of Elderly People to Indoor Air Pollutants in Wanxia Nursing Home

The elderly residing in nursing homes are typically more advanced in age, have more health issues, and spend more time indoors than other elderly people. This study explored the indoor air quality in the Wanxia nursing home, the largest private nursing home in Chengdu, China, based on long-term measurement data. Air pollutant sensors measured the level of air pollution in the Wanxia nursing home from March 2021 to February 2022. This study obtained several important results: (1) The indoor air quality index (IAQI) of the Wanxia nursing home was at a low pollution level in spring, summer, and autumn, and at a moderate pollution level in winter. PM concentration played the most important role in determining indoor air quality; (2) During winter, the 24 h mean indoor concentrations of PM2.5 and PM10 were close to or even exceeded the standard limits. During winter and summer nights, indoor CO2 levels were very close to or greater than 1000 ppm. During spring and summer nights, the indoor TVOC concentrations exceeded the limit (0.45 mg/m3); (3) Apart from HCHO concentrations in autumn, the levels of other indoor air pollutants were significantly influenced by their outdoor levels. In addition, the seasonal indoor/outdoor (I/O) ratios of CO2 and TVOCs exceeded 1; and (4) Indoor CO2 levels were closely related to indoor temperature (Ta) and relative humidity (RH) in each season. PM10 concentration correlated with Ta and RH in summer, while PM2.5 concentration did not correlate with Ta and RH in winter. The indoor TVOC level positively correlated with RH. Lastly, the indoor HCHO level was minimally influenced by changes in Ta and RH. Due to the above results, this study proposes targeted strategies for improving indoor air quality in nursing homes.

Effects of indoor air quality and home environmental characteristics on allergic diseases among preschool children in the Greater Taipei Area

Indoor air quality and home environmental characteristics are potential factors associated with the onset and exacerbation of allergic diseases. Our study examined the effects of these factors on allergic diseases (i.e., asthma, allergic rhinitis, allergic conjunctivitis, and atopic dermatitis) among preschool children. We recruited a total of 120 preschool children from an ongoing birth cohort study in the Greater Taipei Area. A comprehensive environmental evaluation was conducted at each participant's residence and included measurements of indoor and outdoor air pollutants, fungal spores, endotoxins, and house dust mite allergens. A structured questionnaire was used to collect information on the allergic diseases and home environments of participants. Land-use characteristics and points of interest in the surrounding area of each home were analyzed. Other covariates were obtained from the cohort data. Multiple logistic regressions were used to examine the relationships between allergic diseases and covariates. We observed that all mean indoor air pollutant levels were below Taiwan's indoor air quality standards. After adjustment for covariates, the total number of fungal spores and the ozone, Der f 1, and endotoxin levels were significantly associated with increased risks of allergic diseases. Biological contaminants more significantly affected allergic diseases than other pollutants. Moreover, home environmental characteristics (e.g., living near power facilities and gas stations) were associated with an increased risk of allergic diseases. Regular and proper home sanitation is recommended to prevent the accumulation of indoor pollutants, especially biological contaminants. Living away from potential sources of pollution is also crucial for protecting the health of children.

Indoor air pollution in India: sources to solution

The indoor air pollution is important area of concern in modern times where we spent most of time indoors after our daily routine. This is also a serious public health concern in India with more than half of the Indian households relying on solid fuel use. The important sources for indoor air pollution include PM 2.5, VOCs and biological pollutants. Three pronged strategy of source reduction through certain changes, adequate ventilation of living spaces and correct methods of cleaning the indoor air by use of air purifiers and indoor plants will help to reduce the indoor air pollution levels thereby decrease its impact on our health. In this article, we reviewed these strategies. Though all standardised survey shows decreasing trend in the tobacco consumption, it is still at higher level that affects the community. Policy makers should channelize their efforts to use innovative ways for IEC and for controlling addiction.

Calculate modeling of the level of indoor air pollution during its cleaning with air purifiers

The article proposes a computational method for determining the concentrations of pollutants inside a ventilated or cleaned room, taking into account the initial conditions and parameters of the flow rate, incoming or purified air, the volume of the room, the initial concentrations of the pollutant in the atmospheric air and in the room air, the parameters of the efficiency of the air cleaner. The article proposes the solution of two mass transfer equations under known initial conditions for two methods of cleaning rooms. When solving the first equation, a direct mass transfer calculation was carried out, which makes it possible to determine the effect of natural or artificial ventilation used indoors with small linear dimensions on the change in the concentration of the selected air polluting substance in the form of a chemical compound or an aerosol containing biological or chemical pollutants. When solving the second equation, a direct mass transfer calculation was carried out, which makes it possible to determine the effect of the operation of an air purifier used indoors with small linear dimensions on the change in the concentration of the selected air polluting substance in the form of a chemical compound or an aerosol containing biological or chemical pollutants. Calculations allow us to determine the time during which a residential office or industrial space is saturated with pollutants or cleaned to the required air quality standards, taking into account the influence of factors such as pollution of the surface layers of atmospheric air, the appearance of pollutants inside the room, the performance and efficiency of ventilation or air purification systems. The proposed calculation methods can be used to determine changes in the quality of indoor air over time, including taking into account changes in oxygen concentrations and pollutants indoors, determining the effectiveness of ventilation and air purification systems of various capacities in residential, office, medical and industrial premises. Ethics. The study does not require the submission of a biomedical ethics committee opinion or other documents.

Sex-differences in the effects of indoor air pollutants and household environment on preschool child cognitive development

Air pollution, outdoor residential environment, indoor household characteristics, and parental mental health are potential factors associated with child development. However, few studies have simultaneously analyzed the association between the aforementioned factors and preschool child (aged 2–5 years) development. This study investigated the effects of those factors on child development and their potential modifying effects. A total of 142 participants were recruited from a birth cohort study in the Greater Taipei Area, and the evaluation was conducted at each participant's home from 2017 to 2020. Child cognitive development was assessed by psychologists using the Bayley Scales of Infant and Toddler Development and the Wechsler Preschool & Primary Scale of Intelligence. Household air pollutants, outdoor residential environment, indoor household characteristics, parental mental health, and other covariates were evaluated. Multiple regressions were used to examine the relationships between child development and covariates. Stratified analysis by child sex and parental mental health was conducted. Average indoor air pollutant levels were below Taiwan's Indoor Air Quality Standards. After adjustment for covariates, the indoor total volatile organic compounds (TVOCs) level was significantly associated with poor child development (per interquartile range increase in the TVOC level was associated with a 5.1 percentile decrease in child cognitive development). Sex difference was observed for the association between TVOC exposure and child development. Living near schools, burning incense at home, purchasing new furniture, and parental anxiety were related to child development. Indoor TVOC level was associated with poor child cognitive development, specifically with the girls. Indoor and outdoor residential environment and parental anxiety interfered with child development. TVOCs should be used cautiously at home to minimize child exposure. A low-pollution living environment should be provided to ensure children's healthy development.

Early-life exposure to air pollution associated with food allergy in children: Implications for ‘one allergy’ concept

BackgroundThe rapid increase of food allergy (FA) has become the “second wave” of allergy epidemic and is now a major global public health concern. Mounting evidence indicates that early life exposure to air pollution is associated with the “first wave” of allergy epidemic (including asthma, allergic rhinitis and eczema) in children, but little is known about its association with FA. ObjectivesWe hypothesize FA has triple exposure pathways, gut-skin-airway, and investigate the effects of airway exposure to outdoor and indoor air pollution on childhood FA. MethodsA cohort study of 2598 preschool children aged 3–6 years old was conducted in Changsha, China. The prevalence of FA was surveyed using a standard questionnaire by International Study of Asthma and Allergies in Childhood (ISAAC). Exposure to indoor air pollution was assessed by four indicators: new furniture, redecoration, mold or dampness, and window condensation. Exposure to outdoor air pollution was evaluated by the concentrations of PM10, SO2 and NO2, which were obtained from the monitored stations. Both prenatal and postnatal exposure windows were considered. The association between exposure to outdoor/indoor air pollution and childhood FA was estimated by multiple logistic regression models using odds ratio (OR) and a 95% confidence interval (CI). ResultsA total of 14.9% children reported FA. The prevalence was significantly associated with exposure to indoor air pollution, OR (95% CI) = 1.93 (1.35–2.75) for prenatal exposure to mold/dampness and 1.49 (1.07–2.10) and 1.41 (1.04–1.89) respectively for postnatal exposure to new furniture and window condensation. The prevalence of FA was also associated with prenatal and postnatal exposure to outdoor air pollution, particularly the traffic-related air pollutant NO2, with adjusted ORs (95% Cls) respectively 1.24 (1.00–1.54) and 1.38 (1.03–1.85) per interquartile range (IQR) increase. Sensitivity analysis showed that the association between outdoor/indoor air pollution and childhood FA was significant only in young children aged 3–4 years. ConclusionEarly-life exposure to high levels of outdoor and indoor air pollution in China due to the rapid economic growth and fast urbanization in the past decades may contribute to the rapid increase of food allergy (FA) in children. Our study indicates that, in addition to gut and skin, airway may be a new route of food sensitization. Air pollution leads to the first and second waves of allergy epidemics, suggesting a concept of ‘one allergy’ disease.

Assessment of Improved Biomass Cookstove Technologies and Kitchen Characteristics on Indoor Air Quality and Fuel Consumption in Rural Settings of Western, Kenya

Purpose: This study investigated the impact of increased levels of indoor air pollution (IAP) caused due to biomass burning using different technologies in the rural households of Western, Kenya. A comparative assessment of the impact of traditional cookstoves (TCS) and improved cookstoves (ICS) coupled with the characteristics of kitchen was conducted to estimate the PM2.5 and CO concentrations in the micro-environments of kitchen and living area of the households.&#x0D; Methodology: The study incorporated both extensive and intensive real-time indoor air quality (IAQ) monitoring during the two cooking sessions of the day. A multi-stage sampling technique was used in this study and the total target population was 383; where 204 households were selected as the sample size for HH survey and 56 households were selected for indoor air pollution monitoring. Influence of the different types of kitchen characteristics; enclosed, semi-enclosed and open was also comprehensively analyzed to measure its impact on the IAQ. Both UCB-PATS instrument and CO loggers were launched in kitchens for 24 hours. The Kitchen Performance Test (KPT) was applied to demonstrate the effectiveness of stove interventions on household fuel consumption. The pollutant concentrations were reported in terms of 24-h, 1-h peak cooking and long-term time scales. Data was analyzed using Statistical Packages for the Social Sciences (SPSS). Multiple regression analysis was undertaken to evaluate the association between pollutant concentration and kitchen characteristics and to determine a set of variables that best predict the pollutants. Units of analysis included means, standard deviations, minimum values, median values and maximum values and IQR. Spearman’s rank correlation coefficients (r) were used to assess the relationship between mean daily kitchen CO concentrations and kitchen PM2.5 concentrations in order to determine whether all kitchen PM2.5 concentrations were as a result of biomass combustion or there were other microenvironment PM2.5 sources. One-way ANOVA was used to compare the quantified fuel use from different stoves and further multiple tests of mean separation were done according to Tukey’s test of significance at p &lt; 0.05.&#x0D; Findings: The results of the study highlighted that households with improved cookstoves that included the Cheprocket and mud rocket stoves consumed 1.5 kg/day (95% CI: 1.3, 5.8) and 1.3 kg/day (95% CI: 1.2, 5.9) less fuel than households with three-stone stoves respectively. The multiple regression models indicated that well ventilated kitchens (β = 2.556, SE = 1.646, p = .036) using ICS, with cemented floors (β = -.091, SE = .026, p = .001) using Chepkube stove and higher number of windows (β = -4.475, SE = 2.841, p = .031) using Cheprocket stove; (β = -.446, SE = .042, p = .030) using rocket stove; (β = -.045, SE = .010, p = .000) using Chepkube stove were associated with lower kitchen PM2.5 concentrations. The study concludes that usage of ICS coupled with efficient designing of the kitchen can improve the overall IAQ of the household along with immense health benefits.&#x0D; Recommendation: Overall, the study emphasized the need of more user education for improved stoves users for behavioural change to reduce PM and CO kitchen concentrations and exposure.

Measurement Analysis and Superposed Effect of Residential Indoor Air Pollutants in Xi'an

To understand the levels of indoor air pollution and protect public health, our research group conducted monitoring of the concentrations of indoor pollutants (formaldehyde, benzene, toluene, xylene, total volatile organic compounds (TVOC), n-butyl acetate, ethylbenzene, styrene, and undecane) and a health effect assessment for 830 households of Xi'an City from December 2017 to December 2020. Simultaneously, the superposed effect of pollutants was analyzed. The results showed that the exceedance rates of formaldehyde, benzene, toluene, TVOC, and xylene were 92.1%, 39.7%, 11.7%, 8.9%, and 1.2% respectively, among which formaldehyde was the most serious pollutant. There was no significant difference in pollutant concentration and exceedance among different room types. The concentration of pollutants was the highest in summer due to the influence of temperature, humidity, and other factors. The results of the human health risk assessment showed that there were carcinogenic risks of formaldehyde and benzene for different age groups (children, adolescents, adults, and the elderly); children and the elderly were more at risk, whereas xylene, ethylbenzene, and toluene were at low risk (HI<1). The superposed effect of pollutants showed that superposition between indoor pollutants did exist, resulting in the obvious increase in pollutant toxicity. This study provides data reference and scientific basis for the characteristics and healthy effects of indoor residential pollutants in Xi'an City.

An overview of indoor air pollution in the Malaysian kindergarten environment

Abstract The components of indoor air determine the quality of the indoor environment, which affects the health and well-being of inhabitants. Exposure to high levels of indoor air pollution in a kindergarten environment has a detrimental influence on children’s learning performance and increases the risk of respiratory problems that could lead to absenteeism. This paper explores and summarises the literature on indoor air pollution in kindergartens in the Malaysian environment. A review was done by analyzing papers taken from four electronic databases: Scopus, Science Direct, PubMed and Google Scholar. Information on indoor pollution levels and determinants sources were extracted from 17 studies. The most investigated pollutants were carbon dioxide (CO2), particulate matter (PM2.5 and PM10), volatile organic compounds (VOCs), carbon monoxide (CO), fungi and bacteria. Inadequate ventilation systems and overcrowded classrooms all contributed to excessive CO2 levels. Indoor PM2.5 sources are generated from cooking activities while cleaning, opening windows and movement activities of children were the primary sources of coarse particles. High concentrations of VOCs are emitted from a wide variety of indoor sources. Mobile vehicles and the proximity of kindergartens to busy roads were key contributors to higher CO concentrations. The findings highlight the importance of interventions to improve indoor air pollution in kindergarten premises in various settings.

Commuters health risk associated with particulate matter exposures in subway system – Globally

The effects of air pollution within subway systems on public health has far been overlooked. A few previous studies have warned that particulate matter (PM)-bound metals in subway air pose a serious threat to public health, but these have been limited by insufficient risk measurement and limited regional data. Present study aimed to determine the levels of human health risk associated with PM10 and PM2.5-bound trace metals in twelve city subways across North America, Asia, and Europe using the human exposure method. Human health risks were estimated via ingestion, inhalation, and dermal exposure methods. The Monte Carlo statistical method using 50,000 iterations was adopted to calculate the probable risk levels for children and adults. Significant levels of non-cancer and cancer risks (CR) were found in subway systems at all regions, regardless of age, although CR were relatively higher in adults. Inhalation and dermal absorption, in which the acceptable range of carcinogenic risk for subway systems was exceeded. Exposure through ingestion made the greatest contributions to overall CR. Among the all subways Tehran and Seoul were estimated as higher CR zone (Total CR > 10−3). Therefore, the Asian subway systems is not only polluted with respect to particulate matter but also recognized as a highly CR zone among the other continents. Cr and Pb have been identified as PM-bound carcinogenic elements that significantly influence cancer risk by inhalation/dermal absorption and ingestion, respectively. Although, the subway is a convenient transportation system for millions of city inhabitants globally, but these findings support the view that indoor air pollutant levels in subway systems can have a serious impact on the cancerous and non-cancerous risks to human health. Strengthening the regulation of indoor air quality or the application of active air purification techniques in subway systems are highly suggested to manage the worst situation.

Indoor Carbon Dioxide, Fine Particulate Matter and Total Volatile Organic Compounds in Private Healthcare and Elderly Care Facilities.

Poor indoor air quality can have adverse effects on human health, especially in susceptible populations. The aim of this study was to measure the concentrations of dioxide carbon (CO2), fine particulate matter (PM2.5) and total volatile organic compounds (TVOCs) in situ in private healthcare and elderly care facilities. These pollutants were continuously measured in two rooms of six private healthcare facilities (general practitioner’s offices, dental offices and pharmacies) and four elderly care facilities (nursing homes) in two French urban areas during two seasons: summer and winter. The mean CO2 concentrations ranged from 764 ± 443 ppm in dental offices to 624 ± 198 ppm in elderly care facilities. The mean PM2.5 concentrations ranged from 13.4 ± 14.4 µg/m3 in dental offices to 5.7 ± 4.8 µg/m3 in general practitioner offices. The mean TVOC concentrations ranged from 700 ± 641 ppb in dental offices to 143 ± 239 ppb in general practitioner offices. Dental offices presented higher levels of indoor air pollutants, associated with the dental activities. Increasing the ventilation of these facilities by opening a window is probably an appropriate method for reducing pollutant concentrations and maintaining good indoor air quality.

Assessing the indoor air pollution level as per energy ladder and its effect on respiratory health

In rural areas of developing countries, where about 40 % of all people live, the household stove accounts for more of all national fuel combustion occur under cooking pots. The present study was undertaken in Hisar district of Haryana state to assess the indoor air pollution level as per the energy ladder and its effect on respiratory health. The study was conducted in the rural villages of Hisar district and rural women who were using traditional chullah were selected as the sample of the study. Results revealed that most of the women were using chullah for cooking their own food and hara for animal feed with fuel placed on the lower rung of energy ladder i.e. crop waste and dung cakes, wood, kerosene, and LPG. Major health problems faced by women were ‘headache’ and ‘irritation in eyes’ while using the traditional chullah and hara. The majority of them were also having respiratory problems like ‘phlegm’ (mean score-2.7) ‘shortness of breath’ (mean score-2.6), ‘cough’ (mean score-2.5), and ‘wheezing’ (attacks) with mean score of 2.0, respectively. Mean PEFR values for the traditional chullah and hara exposed women were significantly lower as compared with MDV chullah and improved hara. Therefore, it is recommended that the use of cheap improved chullah and hara are the best alternative, which is the permanent solution of smoke and also consumes less fuel than traditional chullah and hara.