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Indoor radon exposure is thought to be associated with adverse health effect as lung cancer. Lung cancer incidences in China have been the highest worldwide during the past two decades. It is important to quantitively address indoor radon exposure and its health effect, especially in countries like China. In this paper, we have conducted a meta‐analysis based on indoor radon and its health effect studies from a systematic review between 2000 and 2020. A total of 8 studies were included for lung cancer. We found that the relative risk (RR) was 1.01 (95% CI: 1.01–1.02) per 10 Bq/m3 increase of indoor radon for lung cancer in China. The subgroup analysis found no significant difference between the conclusions from the studies from China and other regions. The health effect of indoor radon exposure is relatively consistent for the low‐exposure and high‐exposure groups in the subgroup analysis. With a better understanding of exposure level of indoor radon, the outcomes and conclusions of this study will provide supports for next phase of researches on estimation of environmental burden of disease by indoor radon exposures in countries like China. [ABSTRACT FROM AUTHOR]

After decades of development, the indoor environment in China has changed. A systematic review was conducted from peer‐reviewed scientific papers with field test data of indoor radon in China from 2000 to 2020 for three types of buildings. The mean concentrations of indoor radon for dwellings, school buildings, and office buildings are 54.6, 56.1, and 54.9 Bq/m3. The indoor radon concentration was related to seasons, climate regions, ventilation, decoration, and other factors such as soil and outdoor air. Colder seasons, especially in severe colder areas of China, newer decorated buildings, closed windows, and doors were all associated with higher indoor radon concentrations. Variables like climate region and ventilation showed statistical significance in the correlation analysis. Regarding the increasing trend of indoor radon concentration in China during the last two decades, further study of indoor radon is necessary especially for school buildings and office buildings, and will help access its environmental burden of disease in China more accurately. [ABSTRACT FROM AUTHOR]

Indoor ammonia (NH3) pollution has been paid more and more attention in view of its health risk. However, few studies have investigated the exposure level in the non‐occupational environment in China. This study systematically reviewed the indoor ammonia exposure level in different regions, the equivalent exposure concentration of different populations, and the factors that influence indoor air ammonia in residences, offices, and schools in China. The literature published in 1980–2019 from main databases was searched and detailed screened, and finally, 56 related studies were selected. The results illustrated that the median concentration of indoor air ammonia in residences, offices, and school buildings was 0.21 mg/m3, 0.26 mg/m3, and 0.15 mg/m3. There were 46.4%, 71.4%, and 40% of these samples exceeding the NH3 standard, respectively. The national concentrations and the equivalent exposure levels of adults and children were calculated and found to be higher than 0.20 mg/m3. The concentration of ammonia varied greatly in different climate zones and economic development regions. Higher concentrations were found in the severe cold zone and the regions with higher economic level. This review reveals a high exposure risk of indoor air ammonia and the crucial impact of human emission, indoor air temperature, new concrete, and economic level, suggesting further investigation on indoor air ammonia evaluation and health effects. [ABSTRACT FROM AUTHOR]

We surveyed 40 010 three‐ to six‐year‐old children in seven Chinese cities (Beijing, Taiyuan, Urumqi, Shanghai, Nanjing, Changsha, and Chongqing) during 2010‐2012 so as to investigate possible links between home renovation and childhood eczema. Their parents responded to questions on home renovation and childhood eczema. Multivariate and two‐level (city‐child) logistic regression analyses yielding odds ratios with 95% confidence intervals were performed. Sensitivity analyses stratifying data for region, climate, and income level were also performed. The prevalences of childhood eczema in children with different floor and wall covering materials were significantly different and were significantly higher with home renovation during early lifetime. Exposure to synthetic materials significantly increased the risk of childhood eczema by 20%‐25%. The risks (AOR, 95% CI) of current eczema among children in families with solid wood flooring and oil paint wall covering were 1.25 (1.04‐1.49) and 1.35 (1.14‐1.60), respectively. Home renovation during pregnancy was related to children's lifetime and current eczema. [ABSTRACT FROM AUTHOR]

During March 2013–December 2014, we conducted a field study in Shanghai, China. A total of 409 children's bedrooms had valid data for formaldehyde which was continuously measured for 24 h. The daily 24 h-averaged and night 6 h-averaged (00:00–06:00) concentrations were 21.5 μg/m 3 and 22.2 μg/m 3 , respectively. Bedrooms with mechanical ventilation had lower formaldehyde concentrations than those with natural ventilation. In the multiple logistic regression analyses, compared to children in the first quartile of 24 h-averaged formaldehyde, children in fourth quartile had significantly lower odds of lifetime-ever food allergy (adjusted odds ratio (OR), 95% confidence interval (CI): 0.39, 0.16–0.97) and current rhinitis (0.39, 0.18–0.86), but children in the third quartile had significantly higher odd of current common cold (≥3 times) (2.42, 1.02–5.77). Among autumn-inspected children, formaldehyde exposure had significant associations with current common cold (≥3 times) (adjusted OR, 95%CI for 24 h-averaged: 4.88, 1.18–20.21 in increment of 11.7 μg/m 3 ; for 6 h-averaged: 4.41, 1.07–18.19 in increment of 15.7 μg/m 3 ). Significantly more families with case children used household mechanical ventilation and air cleaner than families with control children. Our results indicate that household formaldehyde exposure may increase the risk of childhood common cold. Since it is impossible that formaldehyde exposure in higher concentrations could decrease the risk of current rhinitis and other illnesses, we infer that those “negative” associations could be confounded by the potential behaviour changes for avoidance of household formaldehyde exposure among families with case children. [ABSTRACT FROM AUTHOR]

Objectives: We investigated patterns of multimorbidities among asthma, allergies, and respiratory illnesses in preschool children. We investigated multimorbidities of lifetime asthma, allergic rhinitis, eczema, food allergy, pneumonia, and ear infections; and multimorbidities of current (in the last year before the survey) wheeze, dry cough, rhinitis, eczema, and common cold during childhood. We further analyzed whether prevalences of these multimorbidities were due to chance.Methods: A cross-sectional study was conducted in 72 kindergartens of Shanghai, China. Parents of preschool children were surveyed with a modified ISAAC questionnaire. Observed prevalences (OPs), expected prevalences (EPs), absolute excess comorbidities (AECs), and relative excess comorbidities (RECs) of various combinations of illnesses were calculated to indicate whether the combined illnesses were related.Results: We analyzed questionnaires for children aged 4–6 years, whose 13,335 questionnaires were the majority of the total 15,266 returned questionnaires (response rate: 85.3%). The studied illnesses were common. For children who had more than three lifetime or current illnesses, OPs tended to be higher than EPs. Most OPs and EPs were higher in boys than in girls, and were higher in children with a family history of atopy (FHA) than in children without FHA. AECs and RECs between boys and girls as well as between children with and without FHA were substantially different.Conclusions: Our findings suggest that multimorbidities among childhood asthma, allergies, and respiratory illnesses are likely not random, but rather share etiology. Specific patterns of childhood asthma multimorbidities perhaps differ between boys and girls and between children with and without FHA. [ABSTRACT FROM PUBLISHER]

Objectives: We investigated associations of breastfeeding (BF) durations and patterns and of timing of other dietary introductions with prevalence of asthma, wheeze, hay fever, rhinitis, pneumonia, and eczema among preschool children.Methods: During April 2011-April 2012, we conducted a cross-sectional study in 72 kindergartens from five districts of Shanghai, China and obtained 13,335 questionnaires of children 4–6-years-old. We used multiple logistic regression models to evaluate the target associations.Results: Compared to children who were never BF, children who were exclusively breastfed 3–6 months had the lowest risk of asthma (adjusted odds ratio and 95% confidence interval: 0.81, 0.72–0.91) and wheeze (0.93, 0.87–0.99); and exclusive BF >6 months was significantly associated with a reduced risk of hay fever (0.93, 0.89–0.97), rhinitis (0.97, 0.94–0.99), pneumonia (0.97, 0.94–0.99), and eczema (0.96, 0.93–0.99). No significant associations were found between time when fruits or vegetables were introduced and the studied diseases. Associations were independent of the child's sex and parent's ownership of the current residence. Longer duration BF was only significantly protective when there was no family history of atopy.Conclusions: This study suggests that heredity, but not sex and socioeconomic status, may negatively impact the effect of BF on childhood airway and allergic diseases. Our findings support China's national recommendation that mothers provide exclusive BF for the first four months, and continue partial BF for more than 6 months. [ABSTRACT FROM AUTHOR]

During 2011–2012, we conducted a cross-sectional study and collected 13,335 parent-reported questionnaires for 4-6 year-old children in Shanghai, China. In this study, we investigated associations of LC-HTRH (Living Close to High Traffic Roads or Highways within 200 m of the residence) with childhood health outcomes. In the multiple logistic regression analyses, LC-HTRH was significantly associated with lifetime-ever doctor-diagnosed asthma (adjusted OR, 95% CI: 1.40, 1.16–1.70). LC-HTRH and bedroom floor level had significant interaction effects on lifetime-ever asthma attack and eczema and past-year eczema. In the subanalyses, LC-HTRH was significantly associated with lifetime-ever asthma (1.52, 1.11–2.09) and asthma attack (1.69, 1.11–2.56) among children who lived on the 4th–6th floors. LC-HTRH was significantly associated with the increased odds of lifetime-ever asthma and past-year rhinitis in summer, autumn, and winter among children whose bedroom windows were opened often. Furthermore, more significant associations between LC-HTRH and the studied outcomes were found among children who both lived in low floor levels and came from families who often opened bedroom windows during night than others. Except for lifetime-ever asthma, no significant associations were found between LC-HTRH and all studied outcomes among children from families who did not often open bedroom windows during night in the different floor levels. This study indicates that LC-HTRH might be associated with part of childhood health outcomes. When ambient air is polluted, increasing bedroom ventilation might lead household air quality at low-medium levels worse, and thus increase odds of some childhood allergic and respiratory problems. [ABSTRACT FROM AUTHOR]

Findings for impacts of outdoor air pollutants on birth outcomes were controversial. We performed a retrospective observational study in 2527 preschoolers of Shanghai, China and investigated associations of duration-averaged concentrations of outdoor sulphur dioxide (SO 2), nitrogen dioxide (NO 2), and particulate matter with an aerodynamic diameter ≤ 10 μm (PM 10) in different months and trimesters of gestation, with preterm birth (PB), low birth weight (LBW), term low birth weight (T-LBW), and small for gestational age (SGA). Daily concentrations of outdoor air pollutants were collected in each residence-located district. Parents reported health information. In the multivariate logistic regression analyses, exposures to outdoor NO 2 were consistently associated with the higher odds of LBW and T-LBW. These associations were generally stronger for early months than for later months of the gestation. Adjusted odds ratios generally were larger in multi-pollutant model than in single-pollutant model. Exposure to NO 2 in the first month of the gestation was significantly associated with T-LBW (adjusted OR, 95%CI: 1.91, 1.02–3.58 for increment of interquartile range (18.5 μg/m3); p -value = 0.044) in multi-pollutant model. This association was stronger in girls, renters, and children whose mothers ≥30 years-old, with household dampness-related exposures, and with parental smoking during pregnancy. Our results indicate that exposure to NO 2 during gestation perhaps is a risk factor for LBW and T-LBW, and effects of NO 2 exposures could be greater during early periods than during later periods of gestation. • A retrospective observational study in 2527 preschoolers was conducted. • Exposures to outdoor NO 2 consistently associated with LBW and T-LBW. • These associations were stronger for early months than for later months. • Adjusted ORs were larger in multi-pollutant than single-pollutant model. • No significant associations were found of SO 2 and PM 10 with all outcomes. [ABSTRACT FROM AUTHOR]

Whether ambient air pollution is associated with childhood atopic eczema is controversial. In this paper, we selected 3358 preschool children who had not altered residences since pregnancy from a cross-sectional study during 2011–2012 in Shanghai, China, and obtained parent-reported data regarding childhood atopic eczema using an improved ISAAC questionnaire. We recorded daily concentrations of SO 2 , NO 2 , and PM 10 throughout the child's lifetime (2006–2012), and calculated period-averaged concentrations for each district where the child lived to represent the child's exposure levels of these pollutants during different periods. In the multiple logistic regression analyses adjusted for potential confounders as well as for the other pollutants in the same periods, childhood atopic eczema was significantly associated with increments of NO 2 in the approximate interquartile range (20 μg/m 3 ) during gestational period (adjusted OR, 95% CI for eczema lifetime-ever: 1.80, 1.29–2.49; for eczema in the year prior to the survey: 2.32, 1.57–3.43) and during the first year of life (2.00, 1.40–2.84; 2.16, 1.43–3.28). Exposure to elevated NO 2 in the first two years, three years and total lifetime, as well as exposure to mixtures containing NO 2 in each of these periods, were consistently associated with increased likelihood of childhood eczema. The highest odds ratios were found between exposure to a mixture of SO 2 and NO 2 during total lifetime (increment: 35 μg/m 3 ) and childhood eczema (adjusted OR, 95% CI: 2.80, 1.75–4.48; 3.50, 1.98–6.19). No significant associations were found between childhood eczema and ambient SO 2 and PM 10 individually or in mixtures. This study indicates that gestational and lifetime exposures to ambient NO 2 are risk factors for atopic eczema in childhood. Exposure to ambient SO 2 and PM 10 may enhance the effect of NO 2 exposure on childhood eczema. [ABSTRACT FROM AUTHOR]

Findings are inconsistent in studies for impacts of outdoor air pollutants on airway health in childhood. In this paper, we collected data regarding airway and allergic symptoms in the past year before a survey in 13,335 preschoolers from a cross-sectional study. Daily averaged concentrations of ambient sulphur dioxide (SO 2), nitrogen dioxide (NO 2), and particulate matter with an aerodynamic diameter ≤10 μm (PM 10) in the past year before the survey were collected in the kindergarten-located district. We investigated associations of 12-month average concentrations of these pollutants with childhood airway and allergic symptoms. In the two-level (district-child) logistic regression analyses, exposure to higher level of NO 2 and of PM 10 increased odds of wheeze symptoms (adjusted OR, 95%CI: 1.03, 1.01–1.05 for per 3.0 μg/m3 increase in NO 2 ; 1.22, 1.09–1.39 for per 7.6 μg/m3 increase in PM 10), wheeze with a cold (1.03, 1.01–1.06; 1.22, 1.08–1.39), dry cough during night (1.05, 1.03–1.08; 1.23, 1.09–1.40), rhinitis symptoms (1.11, 1.08–1.13; 1.32, 1.07–1.63), rhinitis on pet (1.11, 1.05–1.18; 1.37, 0.95–1.98) and pollen (1.12, 1.03–1.21; 1.23, 0.84–1.82) exposure, eczema symptoms (1.09, 1.05–1.12; 1.22, 0.98–1.52), and lack of sleep due to eczema (1.12, 1.07–1.18; 1.58, 1.25–1.98). Exposures to NO 2 and PM 10 were also significantly and positively associated with the accumulative score of airway symptoms. Similar positive associations were found of NO 2 and of PM 10 with the individual symptoms and symptom scores among preschoolers from different kindergarten-located district. These results indicate that ambient NO 2 and PM 10 likely are risk factors for airway and allergic symptoms in childhood in Shanghai, China. • We surveyed 13,335 preschoolers from five districts of Shanghai, China. • We studied effects of ambient NO 2 , SO 2 and PM 10 on airway and allergic diseases. • Periods of pollutant exposures and disease appearances were same in one year. • NO 2 and PM 10 was associated with increased risks of most studied diseases. [ABSTRACT FROM AUTHOR]