Indoor Air Quality Guidelines Research Articles

A study on the evaluation of indoor air quality in small scale apartment house in South Korea

The purpose of this study is to measure and evaluate indoor air quality in small-scale apartment houses which are not included in construction standard of Clean-Healthy house in Korea. This study is measured the formaldehyde, acetaldehyde, benzene, toluene, ethylbenzene, xylene and styrene included in the indoor air quality guideline of Korea. As a result, high concentrations of formaldehyde and acetaldehyde were detected in some of the houses measured, and in particular, there were some homes that exceeded the guidelines of the World Health Organization by more than six times the guideline of acetaldehyde. Some of the measured houses were found to contain volatile organic compounds such as toluene, styrene, and xylene at a high concentration and exceeded the indoor air quality in Korea guidelines. Therefore, the construction standards of Clean-Healthy house should be applied not only to large-scale apartment of 1,000 or more, but also to single-family houses and small-scale apartment houses.

Field study on indoor air quality of wood remodeled welfare facilities for physical and psychological benefits

Outdoor pollutants are well documented and monitored due to existing air quality regulations in many parts of the world. However, as information regarding indoor air quality is still limited, there are not enough information for indoor air pollutants. Indoor air quality pollutants are harmful to human health and are especially dangerous to vulnerable populations, such as elderly people and children. The effects of indoor environment and indoor air pollutants on children and the elderly are being studied worldwide. Ultimately, this paper highlights the prospect of remodeling wood interior, an indoor air pollutants reduction strategy that will help improve indoor air quality and public health. Wood is an environmentally friendly building material with low thermal conductivity and humidity control, and wood interior remodeling can protect people's health from indoor air pollutants. In this paper, twelve indoor air quality factors were measured: comfort factor (temperature and relative humidity), particulate matter, biological pollutants (total airborne bacteria), Airborne asbestos fibers, and chemical pollutants (carbon monoxide and dioxide, formaldehyde, volatile organic compounds, radon, ozone and nitrogen oxides). The average value of the indoor air quality factors for 12 welfare facilities is as follows. The average particulate matter was less than 12μg/㎥, the average of carbon dioxidewas 754.2 ppm, the formaldehyde was 46.6μg/㎥, the volatile organic compounds was 335.0μg/㎥, the total airborne bacteria was 37.8 CFU/㎥and the radon was 59.5Bq/㎥. As a result, almost all of the measurement locations were found to satisfy the international indoor air quality guidelines. It is thus judged that interior remodeling using wood can improve the indoor air quality of welfare facilities, and that it is necessary to constantly measure indoor air quality for accurate indoor air quality analysis.

Assessment of indirect inhalation exposure to formaldehyde evaporated from water

Volatilization volumes and health risks associated with indirect inhalation exposure to formaldehyde evaporated from water have not been investigated quantitatively. We experimentally investigated formaldehyde volatility, compared with chloroform volatility, predicted formaldehyde inhalation exposure concentrations in Japanese bathrooms, and then re-evaluated drinking water quality standards. Although the Henry's law constant of formaldehyde is 1/104 that of chloroform, with a 30-min exposure period, the formaldehyde non-equilibrium partition coefficient (K'd) was 1/500th the chloroform value because of formaldehyde's faster volatilization rate. We used this ratio to estimate the cumulative probability distribution of formaldehyde concentrations in bathroom air. For a formaldehyde concentration in water of ≤2.6 mg/L-water (WHO tolerable concentration), the probability that the incremental formaldehyde concentration due to volatilization would exceed 100 μg/m3-air (WHO indoor air quality guideline) was low. However, major sources of formaldehyde in indoor air are building materials and furniture. We therefore calculated the allowable concentration in water by allocating a small percentage of the indoor air guideline value to indirect inhalation exposure via volatilization from tap water. With an allocation factor of 20% (10%), the allowable concentration was 0.52 (0.26) mg/L-water. These concentrations are similar to the Health Canada guideline concentration but they are 3–6 times the Japanese water quality standard.

A strategy for the reduction of formaldehyde concentration in a hospital pathology laboratory

ObjectivesFormaldehyde is routinely used in pathology laboratories. The threshold limit value of formaldehyde determined by American and Japanese organizations is 0.1 ppm, which is similar to the indoor air quality guideline value (0.08 ppm). Therefore, maintaining low formaldehyde concentrations in the workplace is imperative. The purpose of this study was to reduce the concentration of formaldehyde in a hospital pathology laboratory, in which approximately 15 000 pathological diagnoses are conducted yearly, using hardware and software interventions.MethodsAlthough this laboratory had various ventilation systems, the formaldehyde concentration was high. Based on the Japanese work environment measurement system, the workplace was categorized as control class III, suggesting that improvements to workplace conditions were required. First, engineering controls were implemented and workers were asked not to block the ventilation system and not to keep waste fluid tanks open. However, the workplace required further improvement. Next, using a video camera and a formaldehyde detector, we attempted to visually educate workers about how much formaldehyde is emitted from the sample container based on the type of action undertaken.ResultsAfter the first intervention, the workplace improved to control class II. Control class II indicates that the workplace condition is between classes I and III; a good workplace condition is classified as class I. Although the work environment was still categorized as control class II after the second intervention, this intervention led to the further improvements.ConclusionsThe hardware and software interventions and safe working habits were effective in improving the work environment.

An overview of health hazards of volatile organic compounds regulated as indoor air pollutants.

Indoor air quality (IAQ) standards and guidelines for volatile organic compounds (VOCs) have been stipulated by various national and international agencies. The main purpose of this paper is to establish an overview of indoor VOCs regarding their impacts on human health. Herein, 13 VOCs were designated as indoor air pollutants (IAPs) in the IAQ standards and guidelines. They were further grouped into four types: nonchlorinated aromatic compounds, chlorinated aromatic compounds, chlorinated aliphatic compounds and aldehydes. For this purpose, the present study discusses the criteria for designating VOCs, and summarizes their main sources in indoor environments. Because the occupational exposure limit (OEL) in workplaces has often used as a preliminary basis for establishing acceptable health-based IAQ guidelines in buildings and residences, this paper thus reviews the OEL values, especially in the American Conference of Governmental Industrial Hygienists (ACGIH)-threshold limit value (TLV). In addition, this paper also reviews the information about the classification of carcinogenicity in human by the international agencies for these VOCs. It shows that human tissues, including kidney, liver, leukemia, nasal cavity, paranasal sinus, liver and bile duct, could be more involved in the development of cancers or tumors when people are exposed to these VOCs through inhalation route in buildings over a long period of time.

Health Risk Assessment of Inhalation Exposure to Long-Chain Aliphatic Hydrocarbons and Aldehydes, TMB, MCH, and MIBK in Indoor Environments

Background:In the past decades, indoor air pollution has become a major public health concern. Therefore, Japan has established indoor air quality guidelines for 13 chemicals, including formaldehyd...

On the Development of Health-Based Ventilation Guidelines: Principles and Framework.

This paper summarizes the results of HealthVent project. It had an aim to develop health-based ventilation guidelines and through this process contribute to advance indoor air quality (IAQ) policies and guidelines. A framework that allows determining ventilation requirements in public and residential buildings based on the health requirements is proposed. The framework is based on three principles: 1. Criteria for permissible concentrations of specific air pollutants set by health authorities have to be respected; 2. Ventilation must be preceded by source control strategies that have been duly adopted to improve IAQ; 3. Base ventilation must always be secured to remove occupant emissions (bio-effluents). The air quality guidelines defined by the World Health Organization (WHO) outside air are used as the reference for determining permissible levels of the indoor air pollutants based on the principle that there is only one air. It is proposed that base ventilation should be set at 4 L/s per person; higher rates are to be used only if WHO guidelines are not followed. Implementation of the framework requires technical guidelines, directives and other legislation. Studies are also needed to examine the effectiveness of the approach and to validate its use. It is estimated that implementing the framework would bring considerable reduction in the burden of disease associated with inadequate IAQ.

Indoor air pollutant exposure and determinant factors controlling household air quality for elderly people in Hong Kong

This study investigated the levels and determinant factors of indoor air pollutants including fine particles (PM2.5), nitrogen dioxide (NO2), and formaldehyde (HCHO) in 55 households exclusively for the elderly in Hong Kong during summer and winter (Jul.–Sep. 2016 and Nov. 2016–Mar. 2017). The average concentrations of PM2.5, NO2, and formaldehyde were 25.3 ± 15.0, 40.5 ± 16.0, and 26.1 ± 22.8 μg/m3 in summer and 34.2 ± 19.0, 43.5 ± 17.0, and 15.4 ± 4.5 μg/m3 in winter, respectively. There were ~ 50.3% of households exceeding the World Health Organization indoor air quality standard for PM2.5 throughout the study, with ~ 40.6 and ~61.0% of the households in summer and winter, respectively. The determinant factors for indoor PM2.5 and NO2 concentrations were identified as from incense burning and cooking. Cooking with suitable ventilation is an important factor to ease indoor pollutant concentrations. Both of PM2.5 and NO2 indoor concentrations showed good correlations with outdoor concentrations. Winter was observed with higher pollutant concentrations than summer except for formaldehyde concentrations. Major factors controlling indoor formaldehyde concentrations are temperature and humidity. The outcome will be useful for the development of future indoor air quality guidelines for Hong Kong.

Ensuring Traceability Using qNMR in the Quantitative Analysis of Formaldehyde and Acetaldehyde

Currently, indoor air quality guidelines for formaldehyde and acetaldehyde are set by the Ministry of Health, Labour and Welfare of Japan. Aldehydes are widely used in adhesives and preservatives, and exposure to these compounds via indoor air is a matter of concern. Considering that contact with indoor air is part of daily life, evaluation of indoor air quality is extremely important. 2,4-Dinitrophenylhydrazine (DNPH) derivatization is widely used for quantitative analysis of aldehydes. A certified reference material with traceability to the International System of Units (SI) is required for this method. However, currently, there are no certified reference materials available for aldehyde-DNPH derivatives, which means that the quantified values obtained by this method are not sufficiently reliable. In this study, we determined the actual content and purity of commercially available aldehyde-DNPH derivatives using 1H-quantitative NMR (qNMR), which can be measured with SI-traceability. Although the commercial DNPH derivatives of formaldehyde and acetaldehyde were low concentration solutions, we were able to determine their purities using 1H-qNMR. Furthermore, we were able to separate and quantify the acetaldehyde isomers generated by the derivatization reaction. In conclusion, it is possible to obtain highly accurate results using 1H-qNMR with commercially available reagents that are not certified metrologically.

Streamlining IAQ guidelines and investigating the effect of door opening/closing on concentrations of VOCs, formaldehyde, and NO2 in office buildings

Indoor air quality (IAQ) 'standards' and 'guidelines' were established by international organizations to reduce harmful concentrations to an acceptable minimum to protect building occupants from detrimental health effects. Three major pollutants are commonly found in the indoor environment; these are volatile organic compounds (VOCs), formaldehyde (CH2O), and nitrogen dioxide (NO2). The objective of this study is two folds: first, guidance is presented for selecting the proper 'standards' and 'guidelines' when investigating IAQ problems. Second, an investigation is carried out to determine the effect of door opening and closing on the concentrations of VOCs, CH2O, and NO2 in office buildings in Kuwait during three wave periods (pre-, post-, summer) at three temperature settings (17 °C, 26 °C, AC shutdown). A modern office building in Kuwait was selected for the study. T-tests revealed significantly higher concentrations (p = 0.027, 0.018, 0.002 for VOCs, CH2O, NO2, respectively) of all three pollutants when doors were closed. All unstandardized B coefficients for the three pollutants were significantly higher when the doors were closed in comparison to open doors. B coefficients showed no significant association between wave periods, temperature settings, and pollutant concentrations; a finding that can be helpful in setting the air conditioning temperatures toward the higher end of 26 °C for energy savings. Two-way ANOVA test for VOCs showed no interaction effects between door openings and wave periods or temperature setting, indicating that VOC concentrations during the wave periods and temperature settings were not affected by the door opening.

Health Risk Factors for Housing Environment and Risk Management

After the 1990s, many effective measures were taken to improve indoor air pollution in Japan. However, as a result of major changes in building materials, consumer products, and lifestyle, and new scientific findings on health effects associated with indoor environmental pollution, new issues have been indicated, such as chemical pollutants in indoor dusts or indoor pollutants caused by new chemicals that were substituted from chemicals that Indoor Air Quality Guideline was set. On the other hand, scientific evidence for the links between housing environment and health has accumulated substantially in recent decades. Therefore, the World Health Organization (WHO) is developing Housing and Health Guidelines to provide policymakers with recommendations on healthy housing conditions such as thermal comfort, indoor air pollution, crowding, and home injuries. In this paper, the basic principles of healthy housing, the current status of Japanese dwellings, and the recent approaches of WHO are summarized.

Adoption and sustained use of cleaner cooking fuels in rural India: a case control study protocol to understand household, network, and organizational drivers

BackgroundImplementing efficient stoves and clean fuels in low and middle-income countries are critical for improving health of poor women and children and improve the environment. Cleaner biomass stoves, however, perform poorly against the World Health Organization’s indoor air quality guidelines. This has shifted the focus to systematic dissemination and implementation of cleaner cooking systems such as liquefied petroleum gas (LPG) among poor communities. Even when there is some uptake of LPG by poor communities, its sustained use has been low. Concurrent use of LPG with traditional biomass cookstoves compromises reductions in household air pollution and limits health and environmental dividends. Therefore understanding key drivers of adoption and sustained implementation of clean fuels among the poor is critical. There is a significant gap, however, in the research to understand determinants and sustained exclusive use of clean fuels in rural poor communities.Methods/designUsing a case control study design, this study will explore the impact of affordability, accessibility, and awareness on adoption and sustained use of LPG among rural poor communities of India. The study uses a multistage random sampling to collect primary data from 510 households. Case group or LPG adopters constitute 255 households while control group or non-LPG adopters constitute the remaining 255 households. The study will deploy sophisticated stove use monitoring sensors in each of the stoves in 100 case group households to monitor stove use and stacking behavior (using clean and traditional systems of cooking) of participants for 12 months. Moreover, this will be the first study to explore the impact of personal social networks striated by gender on LPG adoption. This study is guided by the RE-AIM (Reach, Effectiveness, Adoption, Implementation, and Maintenance) implementation science evaluation framework.DiscussionLessons from this study will feed into a larger discussion on developing a pro-poor strategy to foster uptake and sustained use of cleaner cooking systems such as LPG. Understanding the determinants of adoption and sustained use of cleaner cooking systems through the RE-AIM framework will expand our insights on implementation of cleaner cooking systems among poor communities and will advance implementation science in the clean cooking sector. A thorough study of such implementation strategies is crucial to realize multiple UN Sustainable Development Goals on global health, climate change, and energy security.

Physicochemical risk factors for building-related symptoms in air-conditioned office buildings: Ambient particles and combined exposure to indoor air pollutants

We conducted a cross-sectional epidemiological study to examine the correlation between indoor air quality (IAQ) and building-related symptoms (BRSs) of office workers in air-conditioned office buildings. We investigated 11 offices during winter and 13 offices during summer in 17 buildings with air-conditioning systems in Tokyo, Osaka, and Fukuoka, and we included 107 office workers during winter and 207 office workers during summer. We conducted environmental sampling for evaluating IAQ and concurrently administered self-reported questionnaires to collect information regarding work-related symptoms. Multivariate analyses revealed that upper respiratory symptoms showed a significant correlation with increased indoor temperature [odds ratio (OR), 1.55; 95% confidence interval (CI), 1.11–2.18] and increased indoor concentration of suspended particles released from the ambient air pollution via air-conditioning systems (OR, 1.31; 95% CI, 1.08–1.59) during winter. In particular, smaller particles (particle size>0.3μm), which possibly penetrated through the filter media in air-conditioning systems from ambient air, were correlated with upper respiratory symptoms. The use of high-efficiency particulate air filters in air-conditioning systems and their adequate maintenance may be an urgent solution for reducing the indoor air concentration of submicron particles. Several irritating volatile organic compounds (VOCs) (e.g., formaldehyde, acetaldehyde, ethylbenzene, toluene, and xylenes) that were positively correlated with the indoor air concentration among their VOCs, were associated with upper respiratory symptoms, although their indoor air concentrations were lower than those specified by the indoor air quality guideline. A new approach and strategy for decreasing the potential combined health risks (i.e., additive effect of risks) associated with multiple low-level indoor pollutants that have similar hazardous properties are required.

Polycyclic aromatic hydrocarbons (PAH) in Portuguese educational settings: a comparison between preschools and elementary schools

ABSTRACTThe aim of this study was to determine levels and risks due to inhalation exposure to polycyclic aromatic hydrocarbons (PAH) in different educational settings, namely for 3- to 5- year-old and 6- to 10-year-old children. Eighteen PAH (16 priority designated by US Environmental Protection Agency (USEPA) and dibenzo[a,l]pyrene and benzo[j]fluoranthene) were simultaneously collected in indoor and outdoor air at two Portuguese preschools (PS1–PS2) and five elementary schools (ES1–ES5) from March to May 2014. Indoor concentrations at PS and ES were significantly different, with total levels (∑PAHs) 0.721–15.9 ng/m3 at PS1–PS2 and 5.03–23.6 ng/m3 at ES1–ES5. The corresponding outdoor concentrations were, respectively, 1.22–32.7 ng/m3 and 2.6–31.5 ng/m3. Polycyclic aromatic hydrocarbons with 2–3 aromatic rings were predominantly emitted by indoor sources, while compounds with 4–6 aromatic rings were mainly generated by infiltration of ambient PAH pollution to indoors. Excess lifetime risks of lung cancer exceeded the World Health Organization (WHO) designated guideline of 10–5 in both types of schools (15–42-fold at PS; 15–52-fold at ES). However, total (sum of indoor and outdoor exposure) incremental lifetime cancer risks (ILCR) were below the USEPA level of 10–6 at all studied institutions and thus considered negligible. Finally, ILCR due to indoor exposure represented 60–75% and 70–85% of the total ILCR at PS and ES, respectively, thus indicating the need for development and implementation of indoor air quality guidelines in educations settings.

Effectiveness of Six Improved Cookstoves in Reducing Household Air Pollution and Their Acceptability in Rural Western Kenya.

BackgroundHousehold air pollution (HAP) from biomass fuel burning is linked to poor health outcomes. Improved biomass cookstoves (ICS) have the potential to improve HAP.ObjectivesA pre-/post- intervention study assessed the impact of six ICS on indoor air quality and acceptability of ICS to local users in rural Western Kenya.MethodsWe measured mean personal and kitchen level concentrations of particulate matter <2.5μm in diameter (PM2.5, μg/m3) and carbon monoxide (CO, ppm) during the 48-hour period of each ICS use in 45 households. We compared these levels to those observed with traditional 3-stone fire (TSF) use. We assessed ICS acceptability through interviews and focus groups. We evaluated association of stove type, fuel use, and factors related to cooking practices with mean kitchen PM2.5 and CO using multivariable regression.ResultsStove type, exclusive ICS use (vs. concurrent TSF use), and the amount of fuel used were independently associated with kitchen PM2.5 and CO levels. Reductions (95%CI) in mean PM2.5 compared to TSF, ranged by ICS from 11.9% (-2.8–24.5) to 42.3% (32.3–50.8). Reductions in kitchen CO compared to TSF, ranged by ICS from -5.8% (-21.9–8.2) to 34.5% (23.2–44.1). Mean kitchen PM2.5 ranged from 319μg/m3 to 518μg/m3 by ICS. Women thought ICS were easy to use, more efficient, produced less smoke, and cooked faster, compared to TSF. Women also reported limitations for each ICS.ConclusionsWe documented reductions in HAP from ICS compared to TSF. The PM2.5 levels with ICS use were still considerably higher than WHO indoor air quality guidelines. Achieving maximal potential of ICS requires adherence to more exclusive use and addressing user reported ICS limitations.

Patterns of domestic exposure to carbon monoxide and particulate matter in households using biomass fuel in Janakpur, Nepal

Household Air Pollution (HAP) from biomass cooking fuels is a major cause of morbidity and mortality in low-income settings worldwide. In Nepal the use of open stoves with solid biomass fuels is the primary method of domestic cooking. To assess patterns of domestic air pollution we performed continuous measurement of carbon monoxide (CO) and particulate Matter (PM2.5) in 12 biomass fuel households in Janakpur, Nepal. We measured kitchen PM2.5 and CO concentrations at one-minute intervals for an approximately 48-h period using the TSI DustTrak II 8530/SidePak AM510 (TSI Inc, St. Paul MN, USA) or EL-USB-CO data logger (Lascar Electronics, Erie PA, USA) respectively. We also obtained information regarding fuel, stove and kitchen characteristics and cooking activity patterns. Household cooking was performed in two daily sessions (median total duration 4 h) with diurnal variability in pollutant concentrations reflecting morning and evening cooking sessions and peak concentrations associated with fire-lighting. We observed a strong linear relationship between PM2.5 measurements obtained by co-located photometric and gravimetric monitoring devices, providing local calibration factors of 4.9 (DustTrak) and 2.7 (SidePak). Overall 48-h average CO and PM2.5 concentrations were 5.4 (SD 4.3) ppm (12 households) and 417.6 (SD 686.4) μg/m3 (8 households), respectively, with higher average concentrations associated with cooking and heating activities. Overall average PM2.5 concentrations and peak 1-h CO concentrations exceeded WHO Indoor Air Quality Guidelines. Average hourly PM2.5 and CO concentrations were moderately correlated (r = 0.52), suggesting that CO has limited utility as a proxy measure for PM2.5 exposure assessment in this setting. Domestic indoor air quality levels associated with biomass fuel combustion in this region exceed WHO Indoor Air Quality standards and are in the hazardous range for human health.

Health risk assessment of inhalation exposure to cyclic dimethylsiloxanes, glycols, and acetic esters in indoor environments

In the past few decades, indoor air pollution has become a major public concern. Japanese government agency has established indoor air quality guidelines for 13 chemicals, including formaldehyde an...

Characteristics of PM2.5, CO2 and particle-number concentration in mass transit railway carriages in Hong Kong.

Fine particulate matter (PM2.5) levels, carbon dioxide (CO2) levels and particle-number concentrations (PNC) were monitored in train carriages on seven routes of the mass transit railway in Hong Kong between March and May 2014, using real-time monitoring instruments. The 8-h average PM2.5 levels in carriages on the seven routes ranged from 24.1 to 49.8µg/m3, higher than levels in Finland and similar to those in New York, and in most cases exceeding the standard set by the World Health Organisation (25µg/m3). The CO2 concentration ranged from 714 to 1801ppm on four of the routes, generally exceeding indoor air quality guidelines (1000ppm over 8h) and reaching levels as high as those in Beijing. PNC ranged from 1506 to 11,570 particles/cm3, lower than readings in Sydney and higher than readings in Taipei. Correlation analysis indicated that the number of passengers in a given carriage did not affect the PM2.5 concentration or PNC in the carriage. However, a significant positive correlation (p<0.001, R 2=0.834) was observed between passenger numbers and CO2 levels, with each passenger contributing approximately 7.7-9.8ppm of CO2. The real-time measurements of PM2.5 and PNC varied considerably, rising when carriage doors opened on arrival at a station and when passengers inside the carriage were more active. This suggests that air pollutants outside the train and passenger movements may contribute to PM2.5 levels and PNC. Assessment of the risk associated with PM2.5 exposure revealed that children are most severely affected by PM2.5 pollution, followed in order by juveniles, adults and the elderly. In addition, females were found to be more vulnerable to PM2.5 pollution than males (p<0.001), and different subway lines were associated with different levels of risk.

Current Indoor Air Quality in Japan.

People spend more than two thirds of their daily time indoors. Hence, maintaining a healthy indoor environment is indispensable for the prevention of building related illness. In Japan, guidelines for indoor air quality have been established for 13 volatile/semi-volatile organic compounds (VOCs/SVOCs). These guidelines are now under revision by the Committee on Sick House Syndrome: Indoor Air Pollution. In order to gain information on the current indoor air pollutants and their levels, we carried out a nation-wide survey of VOCs and aldehydes in indoor residential air during 2012-2013. In this review, I concisely summarized the current indoor air quality of Japan.

Efficiencies and pollutant emissions from forced-draft biomass-pellet semi-gasifier stoves: Comparison of International and Chinese water boiling test protocols

Biomass fuels are widely combusted in rural China, producing numerous air pollutants with great adverse impacts on human health. Some improved cookstoves and pellet fuels have been promoted. To evaluate the performance of pellet-gasifier stoves, efficiencies and pollutant emissions were measured following International and Chinese water boiling tests (WBTs). Compared with traditional stoves and unprocessed biomass fuels, increased efficiencies and lower emissions of pollutants including carbon monoxide (CO), particulate matter (PM), parent and derivative polycyclic aromatic hydrocarbons (PAHs) were revealed for pellet-gasifier stoves. However, the calculated emission rates (ERs) of CO and PM2.5 cannot meet the ER targets recently suggested by WHO indoor air quality guidelines (IAQGs). Better control of air mixing ratio and gross flow rates of primary and secondary air supply greatly reduced emissions and increased efficiencies. Differences among testing protocols are the key factors affecting the evaluation of stove performance. With longer burning duration and higher power, the Chinese WBT had statistically higher efficiencies, gas temperature, and lower pollutant emissions (p<0.10) compared to those obtained through the International WBT. Statistically significant differences between the two protocols indicate the need for further efforts in emission tests and methodology development before the release of a well-accepted international testing protocol.