Wood Smoke Pollution Research Articles

Comparing the effectiveness of education and technology in reducing wood smoke pollution: A field experiment

This study describes a field experiment assessing the effectiveness of education and technological innovation in reducing air pollution generated by domestic wood heaters. Two-hundred and twenty four households from a small regional center in Australia were randomly assigned to one of four experimental conditions: (1) Education only – households received a wood smoke reduction education pack containing information about the negative health impacts of wood smoke pollution, and advice about wood heater operation and firewood management; (2) SmartBurn only – households received a SmartBurn canister designed to improve combustion and help wood fires burn more efficiently, (3) Education and SmartBurn, and (4) neither Education nor SmartBurn (control). Analysis of covariance, controlling for pre-intervention household wood smoke emissions, wood moisture content, and wood heater age, revealed that education and SmartBurn were both associated with significant reduction in wood smoke emissions during the post-intervention period. Follow-up mediation analyses indicated that education reduced emissions by improving wood heater operation practices, but not by increasing health risk perceptions. As predicted, SmartBurn exerted a direct effect on emission levels, unmediated by wood heater operation practices or health risk perceptions.

Air Pollution in Residential Areas from Wood-fired Heating

An important source of inhalable particles in residential areas, particularly in the winter season, is the biomass combustion when wood is used for domestic heating. This is a continuation of our previous investigation about wood smoke pollution in residential areas of southern Germany (Bari et al., 2009). The target of this study was to characterise ambient levels of criteria pollutants, their risk assessment and find out influence of hardwood combustion on local air quality. Particle-phase PM10 samples were collected at a residential site Dettenhausen near Stuttgart during 2005/06 and winter 2009. Samples were analysed by gas chromatography–mass spectrometry for polycyclic aromatic hydrocarbons (PAHs) and other wood smoke tracer compounds (e.g., levoglucosan, methoxyphenols). High concentrations of PM10 and total PAHs were found during winter 2009 like winter 2005/06. Carcinogenic PAHs were detected in high concentrations and contributed 44% of the total PAHs in the ambient air. The significant concentrations of hardwood markers (i.e., syringaldehyde, acetosyringone) found in the ambient air suggest that the influence of hardwood combustion on ambient air quality is significant. Based on the emission ratio of hardwood markers and PM10, it can be concluded that in the investigated residential site about 57% of ambient PM10 pollution can be attributed to hardwood combustion for winter heating.

Temporal variation and impact of wood smoke pollution on a residential area in southern Germany

This paper is a continuation of our previous publication (Bari, M.A., Baumbach, G., Kuch, B., Scheffknecht, G., 2009. Wood smoke as a source of particle-phase organic compounds in residential areas. Atmospheric Environment 43, 4722–4732) and describes a detailed characterisation of different particle-phase wood smoke tracer compounds in order to find out the impact of wood-fired heating on ambient PM 10 pollution in a residential area near Stuttgart in southern Germany. The results from previous flue gas measurements help distinguishing different tracer compounds in ambient PM 10 samples. In the residential area, significant amounts of hardwood markers (syringaldehyde, acetosyringone, propionylsyringol, sinapylaldehyde) and low concentrations of softwood markers (vanillin, acetovanillone, coniferyldehyde, dehydroabietic acid, retene) were found in the ambient air. The general wood combustion markers Levoglucosan, mannosan and galactosan were detected in high concentrations in all particle-phase PM 10 samples. To find out the size distribution of ambient particles, cascade impactor measurements were carried out. It was found that more than 70% of particulate matter was in the particle diameter of less than 1 μm. Using emission ratio of levoglucosan to PM 10, it can be demonstrated that during winter months 59% of ambient PM 10 pollution could be attributed to residential wood-fired heating.

Spatial variability and population exposure to PM2.5 pollution from woodsmoke in a New South Wales country town

A portable radiance research nephelometer was used to measure the variation in woodsmoke pollution in Armidale (a small town of 22,000 people), New South Wales, Australia, on 14 winter nights in 1996. Winter nights are characterised by inversions that trap the air within the valley and reduce winds to very low speeds (averaging 0.15 m s −1). Pollution varied considerably with location. Mean scattering coefficients (bsp/10 km) for 14 measurement nights ranged from less than 1.0 on the undeveloped fringes of the city to 8.7, the latter representing a 14-night average of 200 μg m −3 of PM2.5. Pollution was generally highest in the residential areas on either side of the valley, where the smoke was generated, rather than the low-lying central creeklands. In places, average pollution levels increased 4-fold within 41 m. The correlation between nephelometer and gravimetric pollution measurements ranged 0.95–0.99. The presence of large, sudden but repeatable changes in air pollution, and high correlations between nephelometer and gravimetric measurements, indicate that mobile pollution monitoring devices provide a useful and accurate estimate of spatial variability. Estimated exposure for the town as a whole was 1.02 for the 6 months from April to September, 0.25 in October as heater use declines, and 0.12 in normal summer months. For comparison, published 25th, 50th and 75th percentiles of the distribution of nephelometer coefficients in Sydney were 0.15, 0.24 and 0.37, respectively. Thus annual exposure to PM2.5 pollution in Armidale from woodsmoke is more than double that from all sources in Sydney, a city of 4 million. Overseas estimates of 6% increased mortality for each additional 10 μg m −3 of PM2.5 suggest that wood heaters in Armidale may increase mortality in Armidale by about 7%, with estimated cost of about $4270 per woodheater per year. Alternative cheap and environmentally friendly methods of keeping houses warm in winter, such as solar heating, should therefore be developed.

Keeping the home fires burning: The affect heuristic and wood smoke pollution

This study examined the role of affect and risk perceptions in maintaining wood burning behavior in 256 residents of a small Australian city characterized by high levels of winter wood smoke pollution. Our analyses revealed that users of wood heaters, relative to non-users, had more positive affective associations with wood heating, perceived fewer health risks from wood smoke, and exhibited less support for wood smoke control policies. Moderation analyses revealed that the predictive effects of risk perceptions on policy support and switching behavior were weaker for respondents who had more positive affective associations with wood heating and stronger for those with more negative affective associations. Theoretical implications relating to the role of affect in decision-making are discussed, together with practical implications for developing more effective interventions to reduce wood smoke pollution.

Childhood asthma and indoor woodsmoke from cooking in Guatemala

We estimated the prevalence and severity of asthma, and the association with cooking on open wood fires, as preparation for a large-scale randomized field trial on effects of indoor air pollution and child health. This is one of the first systematic studies of asthma and indoor wood-smoke pollution and to our knowledge the first asthma study in a purely indigeneous population in Latin America. The mothers of 1058 children aged 4-6 years were interviewed, using the standardized ISAAC (International Study of Asthma and Allergies in Childhood) procedures and questionnaire. The study population is a Mam-speaking (Maya), indigenous group living at relatively high altitude (2000 m) in Western Guatemalan Highlands. We found that asthma prevalence is low among indigenous children in Guatemala, compared to other populations in Latin America. Only 3.3% of the children reported wheezing symptoms in the last 12 months, and 72% wheezing symptoms ever. The majority of the current wheezers had at least one of the criteria for severe asthma. The prevalence of all the symptoms of asthma was higher in children from households that used open fires compared to improved stoves with chimneys. In a logistic regression model, use of open fire for cooking was a significant risk factor for a number of asthma symptoms, with odds ratios varying from 2.0 to 3.5. Among the different cooking technologies (1-improved stove with chimney, 2-mixture of gas and open fire, 3-open fire) trends of higher prevalence with more pollution was found for some of the symptoms. Hence use of open fire for cooking, may be an important risk factor for asthma symptoms and severity.

Tracers of wood smoke

Smoke from wood burning is a significant source of air pollution in many parts of the world. When several sources simultaneously cause air pollution, it is often difficult to determine how much comes from wood burning. Wood smoke has unique chemical characteristics that can be used as indicators, including elemental composition, particularly potassium and chlorine, the ratios of organic and elemental carbon, and gases such as methyl chloride. This paper deals with formulating and applying the chemical mass balance approach incorporating both gas- and aerosol-phase tracers to a study carried out at Olympia-Lacey in Washington. In this study, three types of tracers were measured simultaneously and used to estimate wood smoke pollution during Winter, namely elemental composition and organic carbon in the particle phase and methyl chloride in the gas phase. The results from the different tracers are found to be in agreement. The air pollution at the study site was dominated by wood smoke mostly from low-temperature combustion (about 80%), with additional but smaller contributions from oil furnaces (15%), automobiles (4%) and occasionally from other nearby sources.

Indoor Woodsmoke Pollution Causing Lower Respiratory Disease in Children

Suggested aetiological factors were evaluated in 244 consecutive children presenting with lower respiratory disease at Marondera Hospital, Zimbabwe. Data obtained from these children were compared with information obtained from 500 children seen at the local well baby clinic. There were no differences in the prevalence of malnutrition, breast feeding, overcrowding, poor housing conditions and poverty in these two groups of children. A significant association was identified between lower respiratory disease and exposure to atmospheric woodsmoke pollution in young children. Air sampling within the kitchens of 40 children revealed levels of atmospheric pollution far in excess of the WHO recommended exposure limit. Elevated carboxyhaemoglobin concentrations confirmed childhood smoke inhalation. We suggest that in many Third World communities a chemical pneumonitis resulting from the inhalation of noxious constituents of woodsmoke predisposes to lower respiratory disease in children.

A Questionnaire Study of Respiratory Health in Areas of High and Low Ambient Wood Smoke Pollution

A cross-sectional questionnaire study was conducted to determine whether there were differences in the prevalence of respiratory symptoms between residents of high and of low wood smoke pollution areas. Six hundred questionnaires were mailed to households in each area asking about respiratory symptoms, such as cold, cough, and congestion and wheezing. The response rate was 57% (325 households) in the high wood smoke area and 51% (257 households) in the low wood smoke area. There were no statistically significant differences between symptoms in the two areas when all age groups were combined for analysis. However, there was a trend toward more symptoms in children aged 1-5 years in the high wood smoke area both in an initial questionnaire, which asked about history of symptoms, and in the follow-up questionnaires, which asked about symptoms during the preceding 2 weeks. In particular, for congestion and wheezing, the percentage reported for the initial questionnaire in the high wood smoke area was 46.4 vs 28.6 in the low wood smoke area. This difference was 29.4 vs 0.0 during the second follow-up period. This pattern was not seen in the other age groups. It is concluded that this study supports the work of others who have suggested that wood smoke air pollution aggravates symptoms of respiratory disease in preschool children, despite an apparent absence of effect at older ages.

Identification of methoxylated phenols as candidate tracers for atmospheric wood smoke pollution

More than 70 organic compounds have been identified in unfractionated methylene chloride extracts of soot from residential wood stoves by a combination of capillary gas chromatography coupled with low-resolution mass spectrometry (GC/MS), GC coupled with high-resolution mass spectrometry, and chemical ionization mass spectrometry with deuteriated methanol as the reagent gas. Thirty of the species are derivatives of guaiacol (2-methoxyphenol) and syringol (2,6-dimethoxyphenol), which result from the pyrolysis of wood lignin. Soots from hardwood and pine show similar proportions of the syingol derivatives, but pine soot has much higher proportions of the guaiacol derivatives. Samples collected onto filters backed up by polyurethane foam (PUF) plus in the cooled smoke plume showed that some of the methoxylated phenols were primarily in the vapor phase, while the majority were associated with the particulates. These species are expected to be unique to wood smoke in urban atmospheres and are therefore suggested as tracers for atmospheric wood smoke pollution.

Respiratory abnormalities in Papua New Guinea children: the effects of locality and domestic wood smoke pollution.

Respiratory abnormalities in Papua New Guinea children: the effects of locality and domestic wood smoke pollution.