Krassi Rumchev

Association of domestic exposure to volatile organic compounds with asthma in young children

Aim: To investigate the association between domestic exposure to volatile organic compounds (VOCs) and asthma in young children. Methods: A population based case-control study was conducted in Perth, Western Australia in children aged between 6 months and 3 years. Cases (n = 88) were children recruited at Princess Margaret Hospital accident and emergency department and discharged with asthma as the primary diagnosis; 104 controls consisted of children from the same age group without an asthma diagnosis identified through the Health Department of Western Australia. Information regarding the health status of the study children and characteristics of the home was collected using a standardised questionnaire. Exposure to VOCs, average temperature and relative humidity were measured in winter and summer in the living room of each participating household. Results: Cases were exposed to significantly higher VOC levels (μg/m3) than controls (p<0.01). Most of the individual VOCs appeared to be significant risk factors for asthma with the highest odds ratios for benzene followed by ethylbenzene and toluene. For every 10 unit increase in the concentration of toluene and benzene (μg/m3) the risk of having asthma increased by almost two and three times, respectively. Conclusions: Domestic exposure to VOCs at levels below currently accepted recommendations may increase the risk of childhood asthma. Measurement of total VOCs may underestimate the risks associated with individual compounds.

Volatile Organic Compounds : Do they present a risk to our health?

Indoor air quality has been recognised as a significant health, environment, and economic issue in many countries. Research findings have demonstrated that some air pollutants occur more frequently and at a higher concentration in indoor air than in outdoor air, including volatile organic compounds (VOCs). In this context, the indoor environment can be of crucial importance because modem society spends most of their time indoors, and exposure to VOCs may result in a spectrum of illnesses ranging from mild, such as irritation, to very severe effects, including cancer. These effects have been seen at very low levels of exposure in many epidemiological studies. In this review, we discuss the nature of the VOCs that are ubiquitous in indoor environment and the evidence for adverse health effects associated with exposure to some of these compounds.

Snoring in primary school children and domestic environment: A Perth school based study

BackgroundThe home is the predominant environment for exposure to many environmental irritants such as air pollutants and allergens. Exposure to common indoor irritants including volatile organic compounds, formaldehyde and nitrogen dioxide, may increase the risk of snoring for children. The aim of this study was to investigate domestic environmental factors associated with snoring in children.MethodsA school-based respiratory survey was administered during March and April of 2002. Nine hundred and ninety six children from four primary schools within the Perth metropolitan area were recruited for the study. A sub-group of 88 children aged 4–6 years were further selected from this sample for domestic air pollutant assessment.ResultsThe prevalences of infrequent snoring and habitual snoring in primary school children were 24.9% and 15.2% respectively. Passive smoking was found to be a significant risk factor for habitual snoring (odds ratio (OR) = 1.77; 95% confidence interval (CI): 1.20–2.61), while having pets at home appeared to be protective against habitual snoring (OR = 0.58; 95% CI: 0.37–0.92). Domestic pollutant assessments showed that the prevalence of snoring was significantly associated with exposure to nitrogen dioxide during winter. Relative to the low exposure category (<30 μg/m3), the adjusted ORs of snoring by children with medium (30 – 60 μg/m3) and high exposures (> 60 μg/m3) to NO2 were 2.5 (95% CI: 0.7–8.7) and 4.5 (95% CI: 1.4–14.3) respectively. The corresponding linear dose-response trend was also significant (P = 0.011).ConclusionSnoring is common in primary school children. Domestic environments may play a significant role in the increased prevalence of snoring. Exposure to nitrogen dioxide in domestic environment is associated with snoring in children.

Impacts of household coal and biomass combustion on indoor and ambient air quality in China: Current status and implication.

This review briefly introduces current status of indoor and ambient air pollution originating from household coal and biomass combustion in mainland China. Owing to low combustion efficiency, emissions of CO, PM2.5, black carbon (BC), and polycyclic aromatic hydrocarbons have significant adverse consequences for indoor and ambient air qualities, resulting in relative contributions of more than one-third in all anthropogenic emissions. Their contributions are higher in less economically developed regions, such as Guizhou (61% PM2.5, 80% BC), than that in more developed regions, such as Shanghai (4% PM2.5, 17% BC). Chimneys can reduce ~80% indoor PM2.5 level when burning dirty solid fuels, such as plant materials. Due to spending more time near stoves, housewives suffer much more (~2 times) PM2.5 than the adult men, especially in winter in northern China (~4 times). Improvement of stove combustion/thermal efficiencies and solid fuel quality are the two essential methods to reduce pollutant emissions. PM2.5 and BC emission factors (EFs) have been identified to increase with volatile matter content in traditional stove combustion. EFs of dirty fuels are two orders higher than that of clean ones. Switching to clean ones, such as semi-coke briquette, was identified to be a feasible path for reducing >90% PM2.5 and BC emissions. Otherwise, improvement of thermal and combustion efficiencies by using under-fire technology can reduce ~50% CO2, 87% NH3, and 80% PM2.5 and BC emissions regardless of volatile matter content in solid fuel. However, there are still some knowledge gaps, such as, inventory for the temporal impact of household combustion on air quality, statistic data for deployed clean solid fuels and advanced stoves, and the effect of socioeconomic development. Additionally, further technology research for reducing air pollution emissions is urgently needed, especially low cost and clean stove when burning any type of solid fuel. Furthermore, emission-abatement oriented policy should base on sound scientific evidence to significantly reduce pollutant emissions.

Climate Change and Air Quality: The Potential Impact on Health:

The objectives of the study were to: consider the potential health impacts in Australia and the region arising from changes in air quality occurring as a result of climate change, identify vulnerable groups and potential adaptation measures and discuss the implications for policy. The authors provide an overview of international and national information on the potential health impacts of air pollutants that would most likely be affected by climate change and a discussion of the policy implications. Climate change is likely to have an impact on levels of ozone and possibly particulates, both of which are associated with increased mortality and a range of respiratory and cardiovascular health effects. One of the implications is therefore a possible increase in adverse health effects due to air pollutants. Regional health impact assessments of climate change should address the issue of air quality, consider current coping capacity, and determine the need for adaptation, particularly for vulnerable groups. Implications for policy include the need for improved modeling and forecasting of air pollutant levels, increased efforts to reduce emissions of air pollutants, continued monitoring of air pollutant levels, and monitoring of the incidence of health effects associated with air pollutants in all countries in the region.

Household hygiene practices in relation to dampness at home and current wheezing and rhino-conjunctivitis among school age children

Good household hygiene practices may improve indoor air quality in the domestic environment. Conversely, a ‘hygiene hypothesis’ is challenging the importance of hygiene and sanitation at home. This study aims to investigate the relationship between household hygiene practices and dampness at home and current wheezing, asthma and other allergic conditions among Australian children. Nine hundred and ninety‐six children from four primary schools in Perth, Western Australia, were recruited for a domestic environmental and health survey during March and April of 2002. The results showed that high cleanliness scores were negatively associated with moulds at home before and after adjustment for age of dwelling (p < 0.001). High ventilation scores were inversely related with damp patches, condensation and moulds at home (p < 0.05). However, households with high cleanliness scores appeared to have significantly higher prevalence of current wheezing (p < 0.05) and current rhino‐conjunctivitis (p < 0.05) in children. The association remained even after controlling for confounders such as age and gender of children, asthma history of parents, passive smoking and dampness at home.

The effect of diesel exhaust exposure on blood-brain barrier integrity and function in a murine model

Epidemiological studies indicate that exposure to diesel exhaust (DE) is associated with vascular‐based disorders. To investigate the effect of DE on blood–brain barrier (BBB) function and integrity, 8‐week‐old BALB/c mice were randomized to DE in a cyclical treatment regimen over a 2‐week period. Functional integrity of BBB was determined by considering brain parenchymal abundance of IgG within the hippocampal formation and cortex at 6 h and 24 h intervals following final exposure treatment. Neurovascular inflammation was expressed as the abundance of glial fibrillar acidic protein. Two doses of DE were studied and compared to air‐only treated mice. Mice exposed to DE had substantially greater abundance of parenchymal IgG compared to control mice not exposed to DE. Increased parenchymal glial fibrillar acidic protein at 24 h post‐DE exposure suggested heightened neurovascular inflammation. Our findings are proof‐of‐concept that inhalation of DE can compromise BBB function and support the broader contention that DE exposure may contribute to neurovascular disease risk. Copyright

Indoor Air Quality In Old And New Schools

It has been demonstrated that air pollution is associated with a wide variety of health impacts in humans, especially among the elderly and children. In this preliminary study the exposure levels of formaldehyde, particulate matter with a size less than 2.5 μm in diameter (PM2.5), number of ultra fine particles as well as indoor temperature and relative humidity were measured in six primary schools (three old and three new schools). A total of 20 classrooms were monitored twice a week, at the beginning and at the end of the week. The aim of this study was to compare exposure levels to selected indoor air pollutants between old and new schools located within the Perth metropolitan area, Western Australia. According to the findings the formaldehyde levels were higher than maximum permissible levels recommended by NHMRC in 45% of samples in old schools and 67% of the samples in new schools. In regards to PM2.5 concentrations, most samples were lower than the WHO guideline value of 25 μg/m (24 hour exposure). In terms of ultra fine particles, generally old schools had a higher number of ultrafine particles.

Prevalence of respiratory symptoms among children in rural Myanmar-disease burden assessment attributable to household biomass smoke

More than three billion people continue to rely on solid fuels as their primary source of domestic energy which is associated with elevated concentrations of indoor air pollutants and increased morbidity and mortality both in adults and children. In Myanmar, solid fuel including coal and biomass (such as dung, crop and charcoal) is the main source of energy used in households. A community-based pilot study was conducted in rural Myanmar with the aim to determine the prevalence of childhood respiratory symptoms in association with the use of biomass for cooking. A total of eighty households were recruited and monitored for exposure to particulate matter with size less than 2.5 μm in aerodynamic diameter (PM2.5) and carbon monoxide (CO). In addition, mothers were interviewed to understand their cooking habits, some house characteristics and children’s respiratory health. The study found that PM2.5 and CO were significant contributors for the prevalence of acute respiratory infections and trouble breathing among young children. House characteristics including mosquito coil, associated with children’s respiratory health. The study confirms that domestic environments in developing countries, like Myanmar, continue to have significant health impacts on children.

Health Risk Assessment of Indoor Air Quality, Socioeconomic and House Characteristics on Respiratory Health among Women and Children of Tirupur, South India

Background: Indoor air pollution is still considered as one of the leading causes of morbidity and mortality worldwide and especially in developing countries, including India. This study aims to assess social, housing, and indoor environmental factors associated with respiratory health among mothers and children. Methods: The study was conducted in the city of Tirupur, South India. We quantitatively assessed the indoor exposure to fine particulate matter (PM2.5) and carbon monoxide in relation to respiratory health among women and children. Information on health status, household characteristics and socioeconomic factors was collected using a modified standardised questionnaire. Results: This study demonstrates the significant health impact of housing and socioeconomic characteristics on the burden of respiratory illness among women and children in urban South India. Increased respiratory symptoms were recorded among women and children from low income households, and those who allowed smoking inside. The mean PM2.5 concentration measured in this study was 3.8 mg/m3 which exceeded the World Health Organization (WHO) 24 h guideline value of 0.025 mg/m3. Conclusions: This study is the first to our knowledge carried out in urban South India and the findings can be used for future intervention studies.