Systematically quantifying the dynamic characteristics of PM2.5 in multiple indoor environments in a plateau city: Implication for internal contribution.

People generally spend most of their time indoors, making a comprehensive evaluation of air pollution characteristics in various indoor microenvironments of great significance for accurate exposure estimation. In this study, field measurements were conducted in Kunming City, Southwest China, using real-time PM2.5 sensors to characterize indoor PM2.5 in ten different microenvironments including three restaurants, four public places, and three household settings. Results showed that the daily average PM2.5 concentrations in restaurants, public spaces, and households were 78.4 ± 24.3, 20.1 ± 6.6, and 18.0 ± 4.3 µg/m3, respectively. The highest levels of indoor PM2.5 in restaurants were owing to strong internal emissions from cooking activities. Dynamic changes showed that indoor PM2.5 levels increased during business time in restaurants and public places, and cooking time in residential kitchens. Compared with public places, restaurants generally exhibit more rapid increases in indoor PM2.5 due to cooking activities, which can elevate indoor PM2.5 to high levels (5.1 times higher than the baseline) in a short time. Furthermore, indoor PM2.5 in restaurants were dominated by internal emissions, while outdoor penetration contributed mostly to indoor PM2.5 in public places and household settings. Results from this study revealed large variations in indoor PM2.5 in different microenvironments, and suggested site-specific measures for indoor PM2.5 pollution alleviation.

Global quantification of emerging and legacy per- and polyfluoroalkyl substances in indoor dust: Levels, profiles and human exposure.

This study investigated the occurrence and distribution of per- and polyfluoroalkyl substances (PFASs) in house dust samples from six regions across four continents. PFASs were detected in all indoor dust samples, with total median concentrations ranging from 17.3 to 197 ng/g. Among the thirty-one PFAS analytes, eight compounds, including emerging PFASs, exhibited high detection frequencies in house dust from all six locations. The levels of PFASs varied by region, with higher concentrations found in Adelaide (Australia), Tianjin (China), and Carbondale (United States, U.S.). Moreover, PFAS composition profiles also differed among regions. Dust from Australia and the U.S. contained high levels of 6:2 fluorotelomer phosphate ester (6:2 diPAP), while perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) were predominant in other regions. Furthermore, our results indicate that socioeconomic factors impact PFAS levels. The assessment of human exposure through dust ingestion and dermal contact indicates that toddlers may experience higher exposure levels than adults. However, the hazard quotients of PFASs for both toddlers and adults were below one, indicating significant health risks are unlikely. Our study highlights the widespread occurrence of PFASs in global indoor dust and the need for continued monitoring and regulation of these chemicals.

Indoor and ambient black carbon and fine particulate matter associations with blood biomarkers in COPD patients.

BACKGROUND: Systemic inflammation contributes to cardiovascular risk and chronic obstructive pulmonary disease (COPD) pathophysiology. Associations between systemic inflammation and exposure to ambient fine particulate matter (PM ≤ 2.5 µm diameter; PM2.5), and black carbon (BC), a PM2.5 component attributable to traffic and other sources of combustion, infiltrating indoors are not well described. METHODS: Between 2012 and 2017, COPD patients completed in-home air sampling over one-week intervals, up to four times (seasonally), followed by measurement of plasma biomarkers of systemic inflammation, C-reactive protein (CRP) and interleukin-6 (IL-6), and endothelial activation, soluble vascular adhesion molecule-1 (sVCAM-1). Ambient PM2.5, BC and sulfur were measured at a central site. The ratio of indoor/ambient sulfur in PM2.5, a surrogate for fine particle infiltration, was used to estimate indoor BC and PM2.5 of ambient origin. Linear mixed effects regression with a random intercept for each participant was used to assess associations between indoor and indoor of ambient origin PM2.5 and BC with each biomarker. RESULTS: 144 participants resulting in 482 observations were included in the analysis. There were significant positive associations between indoor BC and indoor BC of ambient origin with CRP [%-increase per interquartile range (IQR);95 % CI (13.2 %;5.2-21.8 and 11.4 %;1.7-22.1, respectively)]. Associations with indoor PM2.5 and indoor PM2.5 of ambient origin were weaker. There were no associations with IL-6 or sVCAM-1. CONCLUSIONS: In homes of patients with COPD without major sources of combustion, indoor BC is mainly attributable to the infiltration of ambient sources of combustion indoors. Indoor BC of ambient origin is associated with increases in systemic inflammation in patients with COPD, even when staying indoors.

Working with cattle slurry on farms: emission and dispersion of hydrogen sulfide gas during stirring.

Over the past 15 years, there have been numerous fatalities related to working with animal slurry. Working with cattle slurry releases toxic gases, in particular, hydrogen sulphide (H2S), which can cause acute central nervous system toxicity, breathing difficulties, and death if exposed to high concentrations. Real-time measurements of H2S gas were taken over distance and time, during the stirring of cattle slurry on farms. Gas was measured at eight slurry stores with differing typical configurations of indoor or outdoor stores and with or without slatted flooring. Highest H2S gas levels were measured from indoor stores under slatted floors, and generally at positions closest to the stirrer or the point of maximum stirring, with levels decreasing with distance from source. Most of the data indicate H2S gas levels increase very rapidly after stirring starts, and mostly decline to baseline levels within 30 min post start of stirring. There were, however, circumstances where gas levels remained high and only started to decline once the stirrer had stopped. H2S gas levels at all farms, at all positions measured were consistently below 10 ppm within 30 min of the stirrer being stopped. The current data highlight areas of the farm and ways of working that have the potential for workers and others to be at risk of exposure to toxic slurry gases. The area should be left to ventilate naturally for at least 30 min after the stirrer has been stopped before re-entering buildings. Influencing the design of stirring equipment and future slurry stores would likely reduce the risk of worker exposure to slurry gases.

The Association Between Solid Fuel Use and Visual Impairment Among Middle-Aged and Older Chinese Adults: Nationwide Population-Based Cohort Study.

BACKGROUND: Indoor air pollution has been reported to have adverse effects on the eye; however, the health effects of exposure to cooking with solid fuels on visual impairment remain unclear in China. OBJECTIVE: We aimed to examine the association between cooking with solid fuels and visual impairment, including distance visual impairment (DVI) and near visual impairment (NVI). METHODS: Data were obtained from the China Health and Retirement Longitudinal Study, a nationwide survey of adults aged over 45 years who were enrolled in 2011 (Wave 1) and followed up in Wave 2 (2013), Wave 3 (2015), and Wave 4 (2018). We used Cox proportional hazards models to determine the association between solid fuels use and visual impairment. Additionally, the impact of switching cooking fuel types on vision function were examined through wave-specific data analysis (Wave 1 and Wave 4). Interaction and subgroup analyses were performed to explore the potential effect modifiers. Data were collected using the stratified multistage random sampling method and further analyzed using SPSS 27.0 and R 4.2.1 statistical software packages. RESULTS: A total of 9559 middle-aged and older Chinese adults without visual impairment at baseline were included in the study, with 51.2% (n=4914) of the participants reporting that they cooked with solid fuels. During the follow-up period, 2644 (27.5%) and 3130 (32.6%) participants developed DVI and NVI, respectively. Compared with the clean fuel users, participants who cooked with solid fuels had a higher risk of DVI (hazards ratio [HR] 1.38, 95% CI 1.28-1.50) and NVI (HR 1.18, 95% CI 1.10-1.27). In addition, switching the cooking fuel type from clean to solid fuels was associated with an elevated risk of DVI (HR 1.51, 95% CI 1.15-1.98) and NVI (HR 1.39, 95% CI 1.06-1.82) compared to persistently using clean fuels during the follow-up period, although no protective effect of switching from solid to clean fuels on NVI was found (P=.52). In subgroup analysis, we found that cooking with solid fuels increased the risk of DVI in participants younger than 65 years (HR 1.41, 95% CI 1.28-1.55), men (HR 1.45, 95% CI 1.28-1.65), urban residents (HR 1.41, 95% CI 1.08-1.75), and smokers (HR 1.43, 95% CI 1.25-1.64). By contrast, negative effects of cooking with solid fuels on NVI were found in nonsmokers (HR 1.21, 95% CI 1.11-1.33) and urban residents (HR 1.20, 95% CI 1.10-1.37). CONCLUSIONS: Cooking with solid fuels was associated with an increased risk of visual impairment among middle-aged and older Chinese adults. These findings indicate that promoting the utilization of clean fuels is conducive to reducing the burden of visual impairment for the public.

Extreme reverse seasonal variations of indoor radon concentration and possible implications on some measurement protocols and remedial strategies.

Indoor radon levels in dwellings are typically higher in cold months than in warm ones. The indoor radon concentration might experience an inverse seasonal behaviour - i.e., radon levels much higher in summer than in winter - under specific circumstances. In the framework of a study on long-term variations of annual radon concentration carried out in some tens of dwellings in Rome and surrounding small towns, two dwellings with very high - up to extreme - reverse seasonal variations were accidently discovered. These dwellings were located in a volcanic area, and they are both south-oriented and located on the lower part of a hill. In one of them, radon concentration was monitored by a continuous radon monitor for two years to find out when the greatest rises in radon levels occur. The indoor radon concentration resulted to experience extremely rapid, i.e. very few hours, increases up to 20 000 Bq m-3 during the spring period (i.e., April, May, and June especially). After about ten years from the first observation, the indoor radon concentration of the same house was monitored again for about five years: radon concentration peaks previously observed were found to be unchanged in terms of absolute values, duration, rising time and occurrence period. These reverse seasonal variations may lead to significant underestimation of the actual annual average radon concentration in case of measurements lasting less than one year if performed during the cold season and especially when seasonal correction factors are used. Moreover, these results suggest adopting specific measurement protocol and remediation strategies in houses having some peculiar characteristics, mainly regarding orientation, position, and attachment to the ground.

Assessment of cyclic volatile methyl siloxanes (CVMSs) in indoor dust from different micro-environments in northern and central Vietnam.

Comprehensive studies on emerging contaminants like volatile methyl siloxanes in settled dust from different micro-environments are still limited. In this study, concentrations and distribution of cyclic volatile methyl siloxanes (CVMSs) including D3, D4, D5, and D6 were examined in indoor dust samples collected from various micro-environments in northern and central Vietnam. Concentrations of total CVMSs in the dust samples ranged from 86.0 to 5890 (median 755) ng/g and decreased in the order: waste processing workshops (median 1560; range 329-5890) > common houses (650; 115-1680) > university classrooms (480; 86.0-1540) > vehicle repair shops (295; 126-1950) ng/g. This observation suggests that informal waste processing activities are sources of CVMSs. Among the studied CVMSs, D5 was the most predominant compound (41 ± 14%), followed by D6 (26 ± 13%), D4 (23 ± 12%), and D3 (11 ± 11%). Moderate positive correlations between D3/D4, D4/D5, and D5/D6 were found. Median daily intake doses of D3, D4, D5, and D6 through dust ingestion were 0.016, 0.051, 0.11, and 0.054 ng/kg/d, respectively, which were comparable to water consumption and markedly lower than the air inhalation pathway.

Household air pollution from solid fuel use as a dose-dependent risk factor for cognitive impairment in northern China.

The relationship between exposure to household air pollution (HAP) from solid fuel use and cognition remains poorly understood. Among 401 older adults in peri-urban northern China enrolled in the INTERMAP-China Prospective Study, we estimated the associations between exposure to HAP and z-standardized domain-specific and overall cognitive scores from the Montreal Cognitive Assessment. Interquartile range increases in exposures to fine particulate matter (53.2-µg/m3) and black carbon (0.9-µg/m3) were linearly associated with lower overall cognition [- 0.13 (95% confidence interval: - 0.22, - 0.04) and - 0.10 (- 0.19, - 0.01), respectively]. Using solid fuel indoors and greater intensity of its use were also associated with lower overall cognition (range of point estimates: - 0.13 to - 0.03), though confidence intervals included zero. Among individual cognitive domains, attention had the largest associations with most exposure measures. Our findings indicate that exposure to HAP may be a dose-dependent risk factor for cognitive impairment. As exposure to HAP remains pervasive in China and worldwide, reducing exposure through the promotion of less-polluting stoves and fuels may be a population-wide intervention strategy to lessen the burden of cognitive impairment.

Temporal and spatial variations in the levels of prominent airborne disinfection by-products at four indoor swimming pools.

Exposure to airborne disinfection by-products, especially trichloramine and trichloromethane, may cause various adverse health effects for the workers and users of indoor swimming pools. This study aims to evaluate the spatial and temporal variations in trichloramine and trichloromethane concentrations within and between swimming pools. Workplace measurements were carried out at four indoor swimming pools in Quebec (Canada) during the cold season. To fully represent daily operating conditions, sampling started 2 hr before the swimming pool opened and continued until 2 hr after closing. To quantify trichloramine and trichloromethane concentrations, 304 air samples have been collected. Temperature, humidity, and CO2 were measured-simultaneously every 2 hr. The results showed that both trichloramine and trichloromethane concentrations varied significantly in time. The observed daily variations in trichloramine and trichloromethane concentrations suggest that the common practice of collecting a single 2-hr air sample does not represent daily pool trichloramine and trichloromethane contamination levels and, consequently, does not represent the true exposure and health risks for workers that are present for a full 8-hr shift. This study recommends a new 8-hr sampling strategy or a full-shift strategy using a cassette with three impregnated filters as a valid and cost-effective solution for comparing time-weighted average (TWA) concentrations to permissible trichloramine exposure limits.

A systematic review on solid fuel combustion exposure and respiratory health in adults in Europe, USA, Canada, Australia and New Zealand.

Epidemiological studies performed in low- and middle-income countries have shown a positive association between solid fuel burning exposure and adverse health effects, including respiratory effects in adults. However, the evidence is less clear in other countries. We performed a systematic review of epidemiological studies conducted in Europe, North America (Canada and USA only), Australia and New Zealand on the association between outdoor and indoor exposure to solid fuel (biomass and coal) combustion and respiratory outcomes in adults. We identified 34 articles. The epidemiological evidence is still limited. Positive associations were found between indoor coal, wood and combined solid fuel combustion exposure and lung cancer risk, although based on a limited number of studies. A significant association was found between indoor solid fuel exposure and COPD risk. Inconsistent results were found considering indoor coal, wood and mixed solid fuel burning exposure and other respiratory outcomes (i.e. lower respiratory infections, upper respiratory infections and other upper respiratory tract diseases, asthma and respiratory symptoms). Inconsistent results were found considering the relationship between the exposure to outdoor wood burning exposure and overall respiratory mortality, asthma, COPD and respiratory symptoms in adults. The available epidemiological evidence between outdoor exposure to residential coal burning and respiratory outcomes suggests an increased risk of adverse respiratory effects. The studies considering the impact of the introduction of measures in order to reduce solid fuel burning on air quality and health showed an improvement in air quality resulting in a reduction of adverse respiratory effects. The identified epidemiological studies have several limitations. Additional and better conducted epidemiological studies are needed to establish whether exposure occurring indoors and outdoors to solid fuel combustion pollutants is associated with adverse respiratory outcomes in adults.

Household air pollution and COPD: cause and effect or confounding by other aspects of poverty?

SETTING: Household air pollution (HAP) and chronic obstructive pulmonary disease (COPD) are both major public health problems, reported to cause around 4 million and 3 million deaths every year, respectively. The great majority of these deaths, as well as the burden of disease during life is felt by people in low- and middle-income countries (LMICs).OBJECTIVE and DESIGN: The extent to which HAP causes COPD is controversial; we therefore undertook this review to offer a viewpoint on this from the Global Initiative for COPD (GOLD).RESULTS: We find that while COPD is well-defined in many studies on COPD and HAP, there are major limitations to the definition and measurement of HAP. It is thus difficult to disentangle HAP from other features of poverty that are themselves associated with COPD. We identify other limitations to primary research studies, including the use of cross-sectional designs that limit causal inference.CONCLUSION: There is substantial preventable morbidity and mortality associated with HAP, COPD and poverty, separately and together. Although it may not be possible to define clear causal links between HAP and COPD, there is a clear urgency to reduce the avoidable burden of disease these inflict on the world´s poor.

Does improving indoor air quality lessen symptoms associated with chemical intolerance?

AIM: To determine whether environmental house calls that improved indoor air quality (IAQ) is effective in reducing symptoms of chemical intolerance (CI). BACKGROUND: Prevalence of CI is increasing worldwide. Those affected typically report symptoms such as headaches, fatigue, 'brain fog', and gastrointestinal problems - common primary care complaints. Substantial evidence suggests that improving IAQ may be helpful in reducing symptoms associated with CI. METHODS: Primary care clinic patients were invited to participate in a series of structured environmental house calls (EHCs). To qualify, participants were assessed for CI with the Quick Environmental Exposure and Sensitivity Inventory. Those with CI volunteered to allow the EHC team to visit their homes to collect air samples for volatile organic compounds (VOCs). Initial and post-intervention IAQ sampling was analyzed by an independent lab to determine VOC levels (ng/L). The team discussed indoor air exposures, their health effects, and provided guidance for reducing exposures. FINDINGS: Homes where recommendations were followed showed the greatest improvements in IAQ. The improvements were based upon decreased airborne VOCs associated with reduced use of cleaning chemicals, personal care products, and fragrances, and reduction in the index patients' symptoms. Symptom improvement generally was not reported among those whose homes showed no VOC improvement. CONCLUSION: Improvements in both IAQ and patients' symptoms occur when families implement an action plan developed and shared with them by a trained EHC team. Indoor air problems simply are not part of most doctors' differential diagnoses, despite relatively high prevalence rates of CI in primary care clinics. Our three-question screening questionnaire - the BREESI - can help physicians identify which patients should complete the QEESI. After identifying patients with CI, the practitioner can help by counseling them regarding their home exposures to VOCs. The future of clinical medicine could include environmental house calls as standard of practice for susceptible patients.

Household Air Pollution and Respiratory Symptoms a Month Before and During the Stringent COVID-19 Lockdown Levels 5 and 4 in South Africa.

Background: Household air pollution (HAP) is associated with adverse human health impacts. During COVID-19 Lockdown Levels 5 and 4 (the most stringent levels), South Africans remained at home, potentially increasing their exposure to HAP. Objectives: To investigate changes in fuel use behaviours/patterns of use affecting HAP exposure and associated HAP-related respiratory health outcomes during COVID-19 Lockdown Levels 5 and 4. Methods: This was a cross-sectional online and telephonic survey of participants from an existing database. Logistic regression and McNemar's test were used to analyse household-level data. Results: Among 2 505 participants, while electricity was the main energy source for cooking and heating the month before and during Lockdown Levels 5 and 4, some households used less electricity during Lockdown Levels 5 and 4 or switched to "dirty fuels." One third of participants reported presence of environmental tobacco smoke in the home, a source of HAP associated with respiratory illnesses. Prevalence of HAP-related respiratory health outcomes were <10% (except dry cough). Majority of households reported cooking more, cleaning more and spending more time indoors during Lockdown Levels 5 and 4 - potentially exposed to HAP. Conclusion: Should South Africa return to Lockdown Levels 5 or 4, awareness raising about the risks associated with HAP as well as messaging information for prevention of exposure to HAP, including environmental tobacco smoke, and associated adverse health impacts will be necessary.

Association between household air pollution and nasopharyngeal pneumococcal carriage in Malawian infants (MSCAPE): a nested, prospective, observational study.

BACKGROUND: Household air pollution from solid fuels increases the risk of childhood pneumonia. Nasopharyngeal carriage of Streptococcus pneumoniae is a necessary step in the development of pneumococcal pneumonia. We aimed to assess the association between exposure to household air pollution and the prevalence and density of S pneumoniae carriage among children. METHODS: The Malawi Streptococcus pneumoniae Carriage and Air Pollution Exposure study was a nested, prospective, observational study of children participating in the cluster randomised controlled Cooking and Pneumonia Study (CAPS) in the Karonga Health and Demographic Surveillance System (HDSS) area in northern Malawi. CAPS compared the effects of a cleaner burning biomass-fuelled cookstove (intervention group) with traditional open-fire cooking (control group) on the incidence of pneumonia in children. Eligible children aged 6 weeks or 6 months (those recruited a 6 weeks were also followed up at age 6 months) were identified by the Karonga HDSS centre. Nasopharyngeal swabs were taken to detect S pneumoniae, and infant exposure to particulate matter with a diameter of ≤2·5 µm (PM2·5) exposure was assessed by use of a MicroPEM device. The primary outcome was the prevalence of nasopharyngeal S pneumoniae carriage in all children aged 6 months, assessed in all children with valid data on PM2·5. The effects of the intervention stoves (intention-to-treat analysis) and PM2·5 (adjusted exposure-response analysis) on the prevalence of S pneumoniae carriage were also assessed in the study children. FINDINGS: Between Nov 15, 2015, and Nov 2, 2017, 485 children were recruited (240 from the intervention group and 245 from the control group). Of all 450 children with available data at age 6 months, 387 (86% [95% CI 82-89]) were positive for S pneumoniae. Geometric mean PM2·5 exposure was 60·3 µg/m3 (95% CI 55·8-65·3) in S pneumoniae-positive children and 47·0 µg/m3 (38·3-57·7) in S pneumoniae-negative children (p=0·044). In the intention-to-treat analysis, a non-significant increase in the risk of S pneumoniae carriage was observed in intervention group children compared with control group children (odds ratio 1·36 [95% CI 0·95-1·94]; p=0·093). In the exposure-response analysis, a significant association between PM2·5 exposure and S pneumoniae carriage was observed; a one unit increase in decile of PM2·5 was found to significantly increase the risk of S pneumoniae carriage by 10% (1·10 [1·01-1·20]; p=0·035), after adjustment for age, sex, 13-valent pneumococcal conjugate vaccination status, season, current use of antibiotics, and MicroPEM run-time. INTERPRETATION: Despite the absence of effect from the intervention cookstove, household air pollution exposure was significantly associated with the prevalence of nasopharyngeal S pneumoniae carriage. These results provide empirical evidence for the potential mechanistic association between exposure to household air pollution and childhood pneumonia. FUNDING: Bill & Melinda Gates Foundation.

Association of long-term indoor exposure to fine particles with pulmonary effects in Northern Taiwan.

An association between short-term indoor exposure to fine particles (PM2.5) and acute respiratory effects has been reported. It is still unclear whether long-term indoor exposure to PM2.5 is associated with pulmonary events. This study recruited 1023 healthy adult homeworkers to conduct a prospective observational study from 2010 to 2021. Four repeated home visits per year were conducted for each participant to measure 24-hour PM2.5 and peak expiratory flow rate (PEFR) and to collect blood samples for absolute eosinophil count (AEC) and carcinoembryonic antigen (CEA) analysis. Additionally, a questionnaire related to personal characteristics, health status and home characteristics was conducted for each participant. The mixed-effects models showed a significant association of PM2.5 with increased CEA and AEC and decreased % predicted PEFR. No significant association between low-level PM2.5 exposure (10-year mean level < 10 µg/m3) and adverse pulmonary effects was observed. The present study concluded that long-term indoor exposure to PM2.5 at a concentration higher than 10 µg/m3 was associated with adverse pulmonary effects among healthy adult homeworkers.

Substantial health benefits of strengthening guidelines on indoor fine particulate matter in China.

In 2020, China for the first time developed guidelines for indoor fine particulate matter (PM2.5) in the draft document of indoor air standards, while the associated health implication remains unclear. Here, we first estimated the PM2.5 associated premature deaths was 965 thousand in 2019, with the indoor PM2.5 of outdoor origin accounting for 72.9%. Then, we examined the dynamic mortalities under a scenario matrix of 36 conditions, by incorporating various shared socioeconomic pathways in 2035, the draft guidelines and the contributions of ambient PM2.5 to indoor exposure. Although it may be improbable, the averages of premature deaths associated with ambient PM2.5 will be 1018-1361 thousand in 2035 when the worst-case scenario of guidelines mandating a yearly (rather than daily) indoor PM2.5 concentration of 75 µg/m3, compared to the averages of estimation were 816-1304 thousand for better-case scenario of 35 µg/m3. Under these scenarios, the increase in the number of premature deaths was mainly driven by population aging. In 2035, an ambitious target of yearly indoor PM2.5 concentrations of 15 µg/m3 is anticipated to reduce the number of deaths associated with ambient PM2.5 by approximately 25% of the 2019 baseline. Stricter guidelines to restrict the indoor PM2.5 concentrations are recommended to mitigate the mortality risk in the future.

Cooking stoves and risk of congenital heart disease in Northwest China: A case-control study.

Congenital heart disease (CHD) has become the most common birth defect in recent decades. The aim of our study was to examine the association between stove cooking by women during pregnancy and congenital heart disease in their offspring. To address this question, we conducted a case-control study from 2014 to 2016 in Xi'an, Shaanxi, Northwest China, investigating 326 cases and 1071 controls. The cases included fetuses or newborns diagnosed with CHD based on the International Classification of Disease (ICD)-10. Controls consisted of healthy newborns without birth defects. Multivariate unconditional logistic regression was applied to analyze the effects of stove cooking before and during pregnancy on CHD in offspring. After adjusting for confounding factors, we found that, compared to cooking with gas stoves, electromagnetic, coal, and firewood stoves during pregnancy was associated with increased risk of CHD in offspring [electromagnetic stove (odds ratio (OR): 2.89, 95% confidence interval (CI): 2.02, 4.12); coal stove (OR: 3.94, 95% CI: 2.33, 6.65); firewood stove (OR: 6.74, 95% CI: 3.03, 15.00)]. Additionally, higher cooking frequency was associated with increased risk of CHD [total stoves (OR: 2.27, 95% CI: 1.57, 3.28); gas stove (OR: 2.38, 95% CI: 1.43, 3.95); electromagnetic stove (OR: 2.46, 95% CI: 1.32, 4.58); coal and firewood stoves (OR: 3.09, 95% CI: 1.01, 9.46)]. Our study suggests that using electromagnetic, coal, and firewood stoves for cooking during pregnancy and greater cooking frequency increased the risk of CHD in offspring. More attention to the choice of fuels in cooking by pregnant women would help to reduce the incidence of CHD in children.

Associations between long term exposures to outdoor air pollution and indoor solid fuel use and depression in China.

Depression is one of the most common mental disorders. Effects of air pollution from outdoor and indoor on depression were inconsistent. We assessed 30,139 participants from Northeast China to explore the associations between long term exposures of outdoor and indoor solid fuel use and depressive symptoms. Multiple logistic regressions models as well as multiplicative interaction and additive interaction analysis were used. Outdoor exposures to air pollutants of particulate matter (with an aerodynamic diameter <2.5 µm, [PM2.5], odds ratio [OR] = 1.98 per standard deviation [SD], 95% confidence interval [CI]: 1.78, 2.19; with an aerodynamic diameter <10 µm, [PM10], OR = 1.83, 95% CI:1.68, 2.00), sulfur dioxide (SO2, OR = 1.42, 95% CI: 1.33, 1.52), and nitrogen dioxide (NO2, OR = 1.62, 95% CI: 1.49, 1.76) were significantly associated with higher occurrence of depressive symptoms. A significant linear trend for increased occurrence of depressive symptoms was observed in participants using both solid fuels for cooking and heating (P = 0.04). Indoor air pollution exposures from solid fuel use for heating (OR = 1.16, 95%CI: 1.00, 1.35) and high cooking frequency (OR = 1.17, 95%CI: 1.00, 1.37) were significantly associated with increased occurrence of depressive symptoms. We observed significant interactions of indoor solid fuel use and outdoor air pollution exposures on depressive symptoms (indoor fuel use for cooking and SO2, P value = 0.04; solid fuel use for heating and NO2, P value = 0.02). Solid fuel use for cooking weakened the associations between SO2(relative excess risk due to interaction [RERI] = -1.37, 95% CI: -1.88, -0.86) and depressive symptoms. Solid fuel use for heating weakened the associations between NO2 (RERI = -1.91, 95% CI: -2.55, -1.27) and depressive symptoms. Compared with individual associations, antagonistic interactions of outdoor air pollution and indoor solid fuel use on depressive symptoms might exist. Our findings contribute to better understandings for the associations between air pollution and depressive symptoms, which might be useful for developing effective strategies for depression prevention and air pollution control.