Housing characteristics and indoor environment in relation to children’s asthma, allergic diseases and pneumonia in Urumqi, China

Association between indoor environmental risk factors and pneumonia among preschool children in Urumqi：A case-control study

Background

Pediatric pneumonia presents a significant global health challenge, particularly in low- and middle-income countries. This study aimed to investigate the incidence of pneumonia in preschool children in Urumqi and its association with indoor environmental factors.

Methods

This case-control study collected data from December 2018 to December 2019 on 1522 preschool children in Urumqi (779 boys and 743 girls) who were diagnosed with pneumonia by a physician. A control group of children who had never had pneumonia was matched in a 1:1 ratio based on gender, age, and ethnicity. Using questionnaires, data were collected on children's general characteristics, passive smoking, types of housing, flooring materials, and indoor dampness, analyzing potential factors associated with the incidence of pediatric pneumonia.

Results

Multivariate analysis revealed that cesarean birth (odds ratio [OR] = 1.27; 95 % confidence interval [95%CI] = 1.08-1.48), being an only child (OR = 1.32; 95%CI = 1.13-1.55), antibiotic treatment during the first year of life (OR = 2.51; 95%CI = 1.98-3.19), passive smoking during the mother's pregnancy (OR = 1.62; 95%CI = 1.24-2.13), living in multi-family apartment housing (OR = 1.64; 95%CI = 1.28-2.10) and other types of housing (OR = 1.47; 95%CI = 1.09-1.99), laminate flooring (OR = 1.31; 95%CI = 1.01-1.72), and tile/stone/cement flooring flooring (OR = 1.31; 95%CI = 1.06-1.61), and dampness in dwelling (during first year of mother's pregnancy) (OR = 1.30; 95%CI = 1.04-1.63) were risk factors for pediatric pneumonia. The use of fresh air filtration systems in children's residences (OR = 0.66; 95%CI = 0.50-0.86) was identified as a protective factor.

Conclusion

This study underscores the importance of indoor environmental factors in the prevention of pediatric pneumonia. Public health strategies should consider these factors to reduce the incidence of pneumonia in children. Future research needs to be conducted over a broader geographical range and consider a more comprehensive range of factors influencing pediatric pneumonia.

Asthma and Other Respiratory Diseases of Children in Relation to Personal Behavior, Household, Parental and Environmental Factors in West China

Asthma and other respiratory diseases, which are of great concern in public health, are paid less attention in areas that are less economically developed. This research aimed to study the prevalence of critical respiratory diseases of children living in West China and figure out the potential influencing factors. A total of 575 children under the age of 14 were recruited from Xinjiang, China, to participate in the study in 2022. Information on activity patterns, socioeconomic and parental factors, and household and surrounding environment situations was obtained using a questionnaire survey. Logistic regression models were applied to estimate the odds ratios of respiratory disease prevalence in relation to behavior patterns, household, parental and environmental factors, respectively. The prevalence of ever doctor-diagnosed asthma, doctor-diagnosed bronchitis and current bronchitis were 4.7%, 19.0% and 14.4%, respectively. The prevalence of doctor-diagnosed pneumonia was 8.2%, which was two times higher in urban than rural areas. Longer annual heating duration was significantly associated with higher risks in children's asthma and bronchitis, with an odds ratio (OR) and 95% confidence interval (95% CI) of 3.363 (95% CI: 1.215-9.298) and 1.267 (95% CI: 1.002-1.601), respectively. Opening the window longer in autumn would lead to higher risks of bronchitis, with ORs of 1.165 and 1.133, respectively, for doctor-diagnosed bronchitis and current bronchitis. Residential air pollution and having a residence close to waste incineration plant or garbage station were, respectively, significantly associated with higher risks of doctor-diagnosed bronchitis and asthma. Parental disease history was associated with a higher prevalence of children's asthma and respiratory diseases, whereas breastfeeding and doing physical exercise were, respectively, significantly associated with a lower risk of asthma. A high prevalence of respiratory diseases in children in West China may be partly attributed to longer annual heating time, opening windows longer in autumn, surrounding environmental pollution, as well as parental disease history, whereas promoting physical activity and breastfeeding could be an effective measure to reduce the risk of childhood asthma in West China.

Housing typologies and asthma: a scoping review

Asthma is related to triggers within the home. Although it is recognised that triggers likely occur due to characteristics of housing, these characteristics have not been comprehensively reviewed, and there is a paucity of housing-focused interventions to reduce asthma and asthma symptoms. Following five steps identified by Arksey and O'Malley, we conducted a scoping review of published evidence on the associations between asthma and housing characteristics. We searched three electronic databases (PubMed, Scopus, Web of Science), identifying 33 studies that met our inclusion criteria. Through an iterative approach, we identified nine housing characteristics relevant to asthma onset or exacerbation, categorised as relating to the surrounding environment (location), the house itself (dwelling), or to conditions inside the home (occupancy). We conceptualise these three levels through a housing typologies framework. This facilitates the mapping of housing characteristics, and visualises how they can cluster and overlap to exacerbate asthma or asthma symptoms. Of the three levels in our framework, associations between asthma and locational features were evidenced most clearly in the literature reviewed. Within this category, environmental pollutants (and particularly air pollutants) were identified as a potentially important risk factor for asthma. Studies concerning associations between dwelling features and occupancy features and asthma reported inconsistent results, highlighting the need for greater research in these areas. Interpreting housing-related asthma triggers through this framework paves the way for the identification and targeting of typologies of housing that might adversely affect asthma, thus addressing multiple characteristics in tandem rather than as isolated elements.

Prevalence and indoor environment risk factors of otitis among preschool children in Urumqi, China

OBJECTIVE

To investigate the indoor environmental risk factors to provide measures for the prevention and control of otitis in preschool children.

METHOD

In this cross-sectional study, a questionnaire survey was administered to preschool children aged 2-7 years from 60 kindergartens in six districts of Urumqi City in August 2019. Multiple regression was run to predict influence factors for otitis media in preschool children.

RESULT

A total of 8153 valid questionnaires were collected. After adjusting for age, the prevalence of otitis among preschool children in Urumqi was 13.1%. Multivariate logistic regression showed that previous antibiotic treatment, treatment with one to two antibiotics before 1 year of age, presence of walls with aqueous or latex paint, use of carpet floor bedding in rooms, newly decorated homes of mothers before pregnancy, purchase of new furniture for homes of children at 0-1 year of age, and presence of flowering plants in the residence of children at 0-1 years of age were all identified as risk factors for the development of otitis in children.

CONCLUSION

Parents should also pay attention to indoor living environments, and reduce indoor renovation in the homes of children during their growth and development, which can positively improve children's indoor living environment, thus effectively preventing otitis in preschool children.

Prevalence, risk factors, impact and management of pneumonia among preschool children in Chinese seven cities: a cross-sectional study with interrupted time series analysis

BACKGROUND

Pneumonia is a common disease worldwide in preschool children. Despite its large population size, China has had no comprehensive study of the national prevalence, risk factors, and management of pneumonia among preschool children. We therefore investigated the prevalence of pneumonia among preschool children in Chinese seven representative cities, and explore the possible risk factors of pneumonia on children, with a view to calling the world's attention to childhood pneumonia to reduce the prevalence of childhood pneumonia.

METHODS

Two group samples of 63,663 and 52,812 preschool children were recruited from 2011 and 2019 surveys, respectively. Which were derived from the cross-sectional China, Children, Homes, Health (CCHH) study using a multi-stage stratified sampling method. This survey was conducted in kindergartens in seven representative cities. Exclusion criteria were younger than 2 years old or older than 8 years old, non-permanent population, basic information such as gender, date of birth and breast feeding is incomplete. Pneumonia was determined on the basis of parents reported history of clearly diagnosed by the physician. All participants were assessed with a standard questionnaire. Risk factors for pneumonia, and association between pneumonia and other respiratory diseases were examined by multivariable-adjusted analyses done in all participants for whom data on the variables of interest were available. Disease management was evaluated by the parents' reported history of physician diagnosis, longitudinal comparison of risk factors in 2011 and 2019.

RESULTS

In 2011 and 2019, 31,277 (16,152 boys and 15,125 girls) and 32,016 (16,621 boys and 15,395 girls) preschool children aged at 2-8 of permanent population completed the questionnaire, respectively, and were thus included in the final analysis. The findings showed that the age-adjusted prevalence of pneumonia in children was 32.7% in 2011 and 26.4% in 2019. In 2011, girls (odds ratio [OR] 0.91, 95%CI [confidence interval]0.87-0.96; p = 0.0002), rural (0.85, 0.73-0.99; p = 0.0387), duration of breastfeeding ≥ 6 months(0.83, 0.79-0.88; p < 0.0001), birth weight (g) ≥ 4000 (0.88, 0.80-0.97; p = 0.0125), frequency of putting bedding to sunshine (Often) (0.82, 0.71-0.94; p = 0.0049), cooking fuel type (electricity) (0.87, 0.80-0.94; p = 0.0005), indoor use air-conditioning (0.85, 0.80-0.90; p < 0.0001) were associated with a reduced risk of childhood pneumonia. Age (4-6) (1.11, 1.03-1.20; p = 0.0052), parental smoking (one) (1.12, 1.07-1.18; p < 0.0001), used antibiotics (2.71, 2.52-2.90; p < 0.0001), history of parental allergy (one and two) (1.21, 1.12-1.32; p < 0.0001 and 1.33, 1.04-1.69; p = 0.0203), indoor dampness (1.24, 1.15-1.33; p < 0.0001), home interior decoration (1.11, 1.04-1.19; p = 0.0013), Wall painting materials (Paint) (1.16, 1.04-1.29; p = 0.0084), flooring materials (Laminate / Composite wood) (1.08, 1.02-1.16; p = 0.0126), indoor heating mode(Central heating)(1.18, 1.07-1.30, p = 0.0090), asthma (2.38, 2.17-2.61; p < 0.0001), allergic rhinitis (1.36, 1.25-1.47; p < 0.0001), wheezing (1.64, 1.55-1.74; p < 0.0001) were associated with an elevated risk of childhood pneumonia; pneumonia was associated with an elevated risk of childhood asthma (2.53, 2.31-2.78; p < 0.0001), allergic rhinitis (1.41, 1.29-1.53; p < 0.0001) and wheezing (1.64, 1.55-1.74; p < 0.0001). In 2019, girls (0.92, 0.87-0.97; p = 0.0019), duration of breastfeeding ≥ 6 months (0.92, 0.87-0.97; p = 0.0031), used antibiotics (0.22, 0.21-0.24; p < 0.0001), cooking fuel type (Other) (0.40, 0.23-0.63; p = 0.0003), indoor use air-conditioning (0.89, 0.83-0.95; p = 0.0009) were associated with a reduced risk of childhood pneumonia. Urbanisation (Suburb) (1.10, 1.02-1.18; p = 0.0093), premature birth (1.29, 1.08-1.55; p = 0.0051), birth weight (g) < 2500 (1.17, 1.02-1.35; p = 0.0284), parental smoking (1.30, 1.23-1.38; p < 0.0001), history of parental asthma (One) (1.23, 1.03-1.46; p = 0.0202), history of parental allergy (one and two) (1.20, 1.13-1.27; p < 0.0001 and 1.22, 1.08-1.37; p = 0.0014), cooking fuel type (Coal) (1.58, 1.02-2.52; p = 0.0356), indoor dampness (1.16, 1.08-1.24; p < 0.0001), asthma (1.88, 1.64-2.15; p < 0.0001), allergic rhinitis (1.57, 1.45-1.69; p < 0.0001), wheezing (2.43, 2.20-2.68; p < 0.0001) were associated with an elevated risk of childhood pneumonia; pneumonia was associated with an elevated risk of childhood asthma (1.96, 1.72-2.25; p < 0.0001), allergic rhinitis (1.60, 1.48-1.73; p < 0.0001) and wheezing (2.49, 2.25-2.75; p < 0.0001).

CONCLUSIONS

Pneumonia is prevalent among preschool children in China, and it affects other childhood respiratory diseases. Although the prevalence of pneumonia in Chinese children shows a decreasing trend in 2019 compared to 2011, a well-established management system is still needed to further reduce the prevalence of pneumonia and reduce the burden of disease in children.

Exposure-response relationship of residential dampness and mold damage with severe lower respiratory tract infections among under-five children in Nigeria

Previous epidemiological studies demonstrated an increased risk of respiratory health effects in children and adults exposed to dampness or mold. This study investigated associations of quantitative indicators of indoor dampness and mold exposure with severe lower respiratory tract infections (LRTI) among children aged 1-59 months in Ibadan, Nigeria.

Methods

In-home visits were conducted among 178 children hospitalized with LRTI matched by age (±3 months), sex, and geographical location with 180 community-based children without LRTI. Trained study staff evaluated the indoor environment using a standardized home walkthrough checklist and measured visible dampness and mold damage. Damp-moldy Index (DMI) was also estimated to quantify the level of exposure. Exposure-response relationships of dampness and mold exposure with severe LRTI were assessed using multivariable restricted cubic spline regression models adjusting for relevant child, housing, and environmental characteristics.

Results

Severe LRTI cases were more often male than female (61.8%), and the overall mean (SD) age was 7.3 (1.35) months. Children exposed to dampness <0.3 m² (odds ratio [OR] = 2.11; 95% confidence interval [CI] = 1.05, 4.36), and between 0.3 and 1.0 m² (OR = 2.34; 95% CI = 1.01, 7.32), had a higher odds of severe LRTI compared with children not exposed to dampness. The restricted cubic spline showed a linear exposure-response association between severe LRTI and residential dampness (P < 0.001) but a nonlinear relationship with DMI (P = 0.01).

Conclusions

Residential dampness and DMI were exposure-dependently associated with higher odds of severe LRTI among under-five children. If observed relationships were causal, public health intervention strategies targeted at reducing residential dampness are critically important to mitigate the burden of severe LRTI among under-five children.

Prevalence and influencing factors of wheeze and asthma among preschool children in Urumqi city: a cross-sectional survey

To investigate the prevalence and indoor environmental influencing factors of wheeze and asthma among preschool children in Urumqi, Xinjiang, China to provide a strong basis for prevention and control. In August 2019, a cross-sectional study involving 8153 preschool children was conducted in 60 kindergartens in Urumqi. The ALLHOME-2 questionnaire was used for childhood wheeze and asthma survey, and the dampness in buildings and health (DBH) questionnaire was used for the childhood home dwelling and living environment survey. Multivariate unconditional logistic regression was then used to analyze the potential influencing factors of childhood asthma and wheeze. The prevalence of wheeze and asthma in children was 4.7% and 2.0%, respectively. Multivariate unconditional logistic regression results suggested that ethnicity other than the Han Chinese (odds ratio (OR) 1.39, 95% confidence interval (CI) 1.05-1.84), caesarean section (OR 1.24, 95% CI 1.00-1.53), family history of asthma (OR 5.00, 95% CI 3.36-7.44), carpet or floor bedding at home (OR 1.40, 95% CI 1.05-1.87), purchasing new furniture in the mother's residence during pregnancy (OR 1.58, 95% CI 1.06-2.36), pet keeping in the residence at aged 0-1 year (OR 1.55, 95% CI 1.13-2.13), passive smoking by child in the current residence (OR 1.35, 95% CI 1.01-1.80), and having mould or hygroma in the child's residence at aged 0-1 year (OR 1.72, 95% CI 1.12-2.64) were risk factors for wheeze. In addition, Girls (OR 0.73, 95% CI 0.59-0.90) was a protective factor for wheeze. Caesarean section (OR 1.46, 95% CI 1.06-2.00), family history of asthma (OR 7.06, 95% CI 4.33-11.53), carpet or floor bedding at home (OR 2.20, 95% CI 1.50-3.23), and pet keeping in the residence at aged 0-1 year (OR 1.64, 95% CI 1.04-1.83) were risk factors for asthma, whereas Girls (OR 0.58, 95% CI 0.42-0.80) was a protective factor for asthma. This survey indicates that the purchase of new furniture, the placement of carpet or floor bedding in the child's residence, the pets keeping, room dampness or moldy phenomena, and passive smoking may all contribute to an elevated risk of wheeze or asthma in children.

Risk Factors of Childhood Asthma Among Patients Attending a Tertiary Care Centre in North-East India

Introduction

Asthma is a chronic lung illness marked by a reversible airway blockage. Both genetic and environmental factors influence higher asthma rates. The present study aims to assess the various socio-demographic and environmental factors influencing the causation of childhood asthma among patients attending the Paediatric Department of Gauhati Medical College and Hospital (GMCH), Assam.

Materials and Methods

A total of 150 clinically diagnosed asthma patients of 3–12 years as cases and patients of the same age group free from respiratory diseases with no history of asthma in a 1:1 ratio as controls were selected. A predesigned and pretested proforma was used to collect data, and written informed consent was obtained from all the legal guardians of the participants. Data were analyzed by chi-square test and binary logistic regression using SPSS V20, considering a p-value <0.05 significant.

Results

Urban and male children were found to be at higher risk of developing asthma. Children belonging to the urban locality (OR= 4.53; 95% CI: 1.57–13.09; p<0.05), damp environment (OR= 5.21; 95% CI: 1.23–22.10; p<0.05), lower socioeconomic status (OR= 3.48; 95% CI: 1.34–9.01; p<0.05), presence of pets (OR= 6.77; 95% CI: 1.76–25.99; p<0.05), family history of atopy/ allergy (OR= 43.29; 95% CI: 5.80–323.15 p<0.05), smoking/passive smoking (OR=23.54; 95% CI: 1.41–394.21 p<0.05) and mixed feeding (OR= 4.47; 95% CI: 1.46–13.63 p<0.05) were the significant risk factors of childhood asthma.

Conclusion

Children are vulnerable to environmental-induced asthma. Awareness and preventive measures are necessary to control and reduce the burden of childhood asthma.

Prenatal low-dose antibiotic exposure and children allergic diseases at 4 years of age: A prospective birth cohort study

BACKGROUND

Based on a medical record or questionnaire survey approach, previous epidemiological studies have investigated associations between maternal antibiotic exposure during pregnancy and childhood allergic diseases. However, biomonitoring studies on the prenatal low-dose antibiotic exposure, mainly from the environment and contaminated food, and in relation to children allergic diseases, are missing.

OBJECTIVES

This research aimed to examine the associations between prenatal low-dose antibiotic exposure measured at multiple time points and children current allergic diseases at 4 years of age.

METHODS

The current study including 2453 mother-child pairs was based on the Ma'anshan Birth Cohort study. Selected 41 antibiotics and their two metabolites, which including human antibiotics (HAs), preferred as human antibiotics (PHAs), veterinary antibiotics (VAs) and preferred as veterinary antibiotics (PVAs), in urine samples from 2453 pregnant women were biomonitored through liquid chromatography-triple quadrupole tandem mass spectrometry. Information on children current allergic diseases were collected via validated questionnaires. Generalized estimating equation were used to explore the associations between the repeated measurements of maternal urinary antibiotic over three trimesters and current allergic diseases in children.

RESULTS

The detection rates of nine individual antibiotics in the three trimester during pregnancy are greater than 10%, and the 90th percentile concentration of the detected antibiotics ranges from 0.07 to 22.34 µg/g, and the 95th percentile concentration ranges from 0.17 to 59.57 µg/g. Among the participants, each one-unit concentration increment of sulfamethazine (adjusted OR=1.28, 95% CI: 1.10, 1.49, P-_FDR=0.014) in the first trimester and ciprofloxacin (adjusted OR=1.17, 95% CI: 1.07, 1.28, P-_FDR=0.008) in the second trimester were associated with an increased risk of current eczema in children. In the third trimester, each one-unit concentration increment of oxytetracycline (adjusted OR=1.90, 95% CI: 1.30, 2.78, P-_FDR=0.014) was associated with an increased risk of current asthma in children. Gender-stratified analyses demonstrated that no gender differences were observed in the associations between prenatal antibiotic exposure and current allergic diseases in children.

CONCLUSIONS

Maternal exposure to certain specific VAs or PVAs (sulfamethazine, ciprofloxacin and oxytetracycline) in different trimesters was associated with an increased risk of current asthma and current eczema in 4-year-old children. No gender differences were found in these associations. Further studies are warranted to confirm our findings and explore the potential mechanisms.

Risk factors for current wheeze among school children (6–7 and 13–14 years old) in Khuzestan, Iran

Objectives

In recent years, there has been a clear trend of increasing allergic diseases especially in children, and developing countries are no exception. Thepresentstudy sought to determine the risk factors associated with wheezing among school children aged 6–7 and 13–14 years living in Khuzestan Province, Iran.

Study design

Cross-sectional.

Methods

Data for this cross-sectional study is the history of wheeze in the last 12 months. The participants included 6-7- and 13-14-year-old girls and boys studying in urban schools in Khuzestan Province in 2019. We collected the data using the multi stage sampling technique as suggested in the International Study of Asthma and Allergies in Childhood (ISAAC). The research reviewed the literature and consulted experts to collect the risk factors for demographic and clinical information, environmental exposure and lifestyle.

Results

Eight thousand questionnaires were handed out to both age groups, of which 7344 were completed. Two hundred ninety-nine (4.1 %) of the participants had current wheeze. Three-point four percent (124 individuals) in the 6–7 year age group and 4.8 % in the 13–14-year-old age group had current wheezing. The results of the logistic regression model suggest that the most significant risk factors associated with the chance of developing current wheeze in the both age groups are: being male (OR: 1.46, 95 % CI: 1.12–1.88), being from employed mother families (OR: 1.50, 95 %, CI:1.05–2.08), property ownership (OR:1.36, 95 %, CI:1.04–1.79) bugs in the property (OR: 1.29, 95 %, CI:0.99–1.70) mold in the property (OR: 1.75, 95 %, CI:1.12–2.76), pet(s) in the student's bedroom (OR: 1.75, 95 %, CI: 0.97–3.14), a family history of asthma and allergic diseases (OR: 2.20, 95 %, CI: 1.69–2.87), tobacco smoke exposures in the property (OR: 1.43, 95 %, CI:1.04–1.96), having allergic rhinitis (OR: 7.86, 95 % CI: 5.89–10.50) and eczema (OR: 3.85, 95 % CI: 2.10–7.08).

Conclusions

Families are suggested to adopt strategies to reduce exposure to outdoor air pollutants and contain indoor allergens. More studies are necessary to further explore the effects of modifying and changing these risk factors.

•

3.4 % in the 6–7 year age group and 4.8 % in the 13–14 year age group had current wheezing.

•

In both age groups, current wheeze is more common in boys than girls.

•

Mold in the home, pet in the bedroom and tobacco smoke exposures are the most important risk factors for current wheeze.

Prevalence and influencing risk factors of eczema among preschool children in Urumqi city: a cross-sectional survey

Background

Eczema is a chronic inflammatory disease associated with impaired quality of life. We identified indoor environmental risk factors, to provide strong evidence for the prevention and control of eczema in preschool children.

Methods

Using a cross-sectional study with stratified random cluster sampling, we conducted a self-administered questionnaire survey among 8153 parents of children aged 2–8 years in 60 kindergartens in six districts of Urumqi city during August 2019.

Results

Among 8153 preschool children, 12.0% of the children have been diagnosed with eczema. Multivariate logistic regression analysis showed that caesarean section (odds ratio [OR] = 1.18, 95% confidence interval [CI]: 1.03–1.36), being an only child (OR = 1.36, 95% CI: 1.18–1.57), presence of mould or moisture in the mother’s home before pregnancy (OR = 1.53, 95% CI: 1.17–2.00), presence of flies or mosquitoes in the dwelling currently (OR = 1.31, 95% CI: 1.10–1.55), pets kept in the child’s home currently (OR = 1.23, 95% CI: 1.01–1.51), presence of pets during child’s first year (OR = 1.45, 95% CI: 1.14–1.85), and family history of eczema (OR = 3.53, 95% CI: 2.98–4.19) are the risk factors for the development of eczema, whereas ethnicity other than the Han Chinese (OR = 0.77, 95% CI: 0.61–0.96) is a protective factor for eczema.

Conclusion

Preschool children in Urumqi are at a high risk of eczema, particularly those of the Han Chinese ethnicity. Parents should be attentive to the indoor living environment of children and take actions to reduce indoor humidity, pest control and elimination, and avoid raising pets to reduce the risk of development of eczema in children.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-021-02819-5.

A review of the impact of outdoor and indoor environmental factors on human health in China

The Intergovernmental Panel on Climate Change (IPCC) reported that global climate change has led to the increased occurrence of extreme weather events. In the context of global climate change, more evidence indicates that abnormal meteorological conditions could increase the risk of epidemiological mortality and morbidity. In this study, using a systematic review, we evaluated a total of 175 studies (including 158 studies on outdoor environment and 17 studies on indoor environment) to summarize the impact of outdoor and indoor environment on human health in China using the database of PubMed, Web of Science, the Cochrane Library, and Embase. In particular, we focused on studies about cardiovascular and respiratory mortality and morbidity, the prevalence of digestive system diseases, infectious diseases, and preterm birth. Most of the studies we reviewed were conducted in three of the metropolises of China, including Beijing, Guangzhou, and Shanghai. For the outdoor environment, we summarized the effects of climate change-related phenomena on health, including ambient air temperature, diurnal temperature range (DTR), temperature extremes, and so on. Studies on the associations between temperature and human health accounted for 79.7% of the total studies reviewed. We also screened out 19 articles to explore the effect of air temperature on cardiovascular diseases in different cities in the final meta-analysis. Besides, modern lifestyle involves a large amount of time spent indoors; therefore, indoor environment also plays an important role in human health. Nevertheless, studies on the impact of indoor environment on human health are rarely reported in China. According to the limited reports, adverse indoor environment could impose a high health risk on children.

Indoor exposure levels of bacteria and fungi in residences, schools, and offices in China: A systematic review

Microbes in buildings have attracted extensive attention from both the research community and the general public due to their close relationship with human health. However, there still lacks comprehensive information on the indoor exposure level of microbes in China. This study systematically reviews exposure levels, the community structures, and the impact factors of airborne bacteria and fungi in residences, schools, and offices in China. We reviewed the major literature databases between 1980 and 2019 and selected 55 original studies based on a set of criteria. Results show that the concentration of indoor bacteria varies from 72.5 to 7500 CFU/m³ , with a median value of 1000 CFU/m³ , and the concentration of fungi varies from 12 to 9730 CFU/m³ , with a median value of 526 CFU/m³ . The concentration level of microbes varies in different climate zones, with higher bacterial concentrations in the severe cold zone, and higher fungal concentrations in the hot summer and warm winter zone. Among different buildings, classrooms have the highest average bacteria and fungi levels. This review reveals that a unified assessment system based on health effects is needed for evaluating the exposure levels of bacteria and fungi.

Indoor microbiome and risk of lower respiratory tract infections among children under-five years: A meta-analysis

We investigated whether exposure to microbiome within the indoor environment is associated with risk of lower respiratory tract infections (LRTI) among children under 5 years of age. Electronic scientific repositories; PubMed, Scopus, Web of Science, GreenFILE, EMBASE, and Cochrane library were searched and screened through July 2019 for published reports for inclusion in the meta-analysis. Studies were eligible for inclusion if they reported an adjusted measure of risk for LRTI associated with IM exposure, including the relative risk (RR) or odds ratio (OR) and confidence interval (CI). The pooled OR was computed using the inverse of variance method for weighting. Sensitivity analysis was used to evaluate the effect of individual studies, while heterogeneity was evaluated by I² statistics using RevMan 5.3. Seven studies were eligible for inclusion in our meta-analysis. Exposure to a higher concentration of IM was associated with an increased risk of LRTI [OR:1.20 (1.11, 1.33), P < .0001]. The risk was stronger with exposure to total fungal concentration [OR:1.27 (1.13, 1.44), P < .0001] than visible molds [OR:1.20 (1.07, 1.34, P = .001]. Under-five children exposed to higher IM concentration are likely at increased risk of LRTI. Interventions addressing IM exposure should be considered in the management of LRTI among under-five children.

Damp mouldy housing and early childhood hospital admissions for acute respiratory infection: a case control study

INTRODUCTION

A gap exists in the literature regarding dose-response associations of objectively assessed housing quality measures, particularly dampness and mould, with hospitalisation for acute respiratory infection (ARI) among children.

METHODS

A prospective, unmatched case-control study was conducted in two paediatric wards and five general practice clinics in Wellington, New Zealand, over winter/spring 2011-2013. Children aged <2 years who were hospitalised for ARI (cases), and either seen in general practice with ARI not requiring admission or for routine immunisation (controls) were included in the study. Objective housing quality was assessed by independent building assessors, with the assessors blinded to outcome status, using the Respiratory Hazard Index (RHI), a 13-item scale of household quality factors, including an 8-item damp-mould subscale. The main outcome was case-control status. Adjusted ORs (aORs) of the association of housing quality measures with case-control status were estimated, along with the population attributable risk of eliminating dampness-mould on hospitalisation for ARI among New Zealand children.

RESULTS

188 cases and 454 controls were studied. Higher levels of RHI were associated with elevated odds of hospitalisation (OR 1.11/unit increase (95% CI 1.01 to 1.21)), which weakened after adjustment for season, housing tenure, socioeconomic status and crowding (aOR 1.04/unit increase (95% CI 0.94 to 1.15)). The damp-mould index had a significant, adjusted dose-response relationship with ARI admission (aOR 1.15/unit increase (95% CI 1.02 to 1.30)). By addressing these harmful housing exposures, the rate of admission for ARI would be reduced by 19% or 1700 fewer admissions annually.

CONCLUSIONS

A dose-response relationship exists between housing quality measures, particularly dampness-mould, and young children's ARI hospitalisation rates. Initiatives to improve housing quality and to reduce dampness-mould would have a large impact on ARI hospitalisation.

Home environment and diseases in early life are associated with allergic rhinitis

OBJECTIVE

Risk factors in relation to allergic rhinitis (AR) remain unclear despite considerable interest. This study aimed to analysis the relationship between home environment and diseases in early life and AR.

METHODS

In a case-control survey, 242 AR patients and 258 healthy persons responded to questionnaires designed to capture pre-pregnancy/pregnancy diseases, maternal medication usage, diseases in early life of participants, family allergic history and home environmental factors. Forty risk factors potentially connected with AR were investigated and analyzed with chi-square test and logistic regression.

RESULTS

There was no correlation between mother's disorders such as periodontitis, chronic rhinitis, diabetes etc. and AR (p > 0.05). A logistic regression analysis showed that neonatal jaundice (p < 0.001), respiratory system infection (p < 0.001), diarrhea (p < 0.01), eczema (p < 0.01) in the early life and home environmental factors such as house decoration (p < 0.01), mold environment (p < 0.001), keeping flowers and plants (p < 0.001), passive smoking (p < 0.01) were associated with AR.

CONCLUSION

Diseases in early life and home environment are closely associated with AR.

Residential risk factors for childhood pneumonia: A cross-sectional study in eight cities of China

BACKGROUND

Children's pneumonia is a heavy health burden. Few studies have been carried out on residential risk factors for pneumonia in children. Potential risks associated with dwelling characteristics are still unknown.

METHODS

A cross-sectional study was conducted among children in 8 cities in China during 2010-2011 and 41,176 valid data on children aged 3-8 years old were used in this analysis. To obtain the lifetime-ever incidence of pneumonia in children and identify associations between pneumonia and residential risk factors, chi-square analysis and logistic regression methods were employed. Adjusted odds ratios were used as measures of effect with a 95% confidence interval. Confounding variables in the regression model include children's gender, birthweight, breastfeeding duration, parental smoking and family history of atopy.

RESULTS

The average lifetime-ever incidence of childhood pneumonia was 32.3%. Urban children (33.6%) had more pneumonia than suburban (29.9%) and rural children (24.9%). More residential risk factors were found in urban-dwellings. Boys, low birthweight (<2500 g), breastfeeding duration <6 months, family allergic history, and exposure to parental smoking were found to be associated with higher pneumonia lifetime-ever incidences. Various indicators of dampness, including visible mold spots, damp stains, water damage, water condensation, damp clothing or bedding and mold odor, were also positively associated with pneumonia. Pneumonia incidence increased as the number of dampness indicators increased. Both natural gas and solid cooking fuels were positively associated with pneumonia compared with electricity. Compared with cement, construction materials including synthetic fiber, laminated wood, real wood, paint, emulsion paint and wall paper were positively associated with pneumonia. Daily living habits such as putting bedding to sunshine frequently and cleaning the child's bedroom every day could be effective preventive strategies. A dose-response relationship between the number of residential risk factors and pneumonia was observed when the risk factors number ranged from 7 to 11. Residences with more risk factors had higher lifetime-ever pneumonia odds ratios.

CONCLUSIONS

Indoor environmental factors including dampness, use of solid fuels or natural gas for cooking and use of new construction materials are risk factors for childhood pneumonia. This study gives evidence for the importance of home environment exposures in the occurrence of childhood pneumonia. Actions against the residential risk factors described in this study may help to prevent pneumonia in children.

Household environment, lifestyle behaviors, and dietary habits in relation to childhood atopic eczema in Shanghai, China

PURPOSES

We aim to investigate associations of the child's individual characteristics, building characteristics, home environmental exposures, family lifestyle behaviors, and dietary habits on childhood eczema during lifetime-ever and in the last year before the survey.

METHODS

During April 2011-April 2012, we conducted a cross-sectional study and collected 13,335 parents-reported questionnaires of 4-6-year-old children from 72 kindergartens in Shanghai, China. Logistic regression model was used to investigate associations.

RESULTS

After adjusted for sex, age, family history of atopy, and questionnaire reporter, the factors which were strongly associated (increased odds >30% and p value <0.05) with lifetime-ever eczema included mother employed during pregnancy (adjusted OR 1.33), residence renovated during pregnancy (1.49) and in the child's first year of life (1.31), using laminate (1.58) and solid (1.42) wood as material of floor covering (compared to using cement), residence located in urban district (1.38), and dampness-related exposures in the early residence (mold spots/stains: 1.41; mold odor: 1.41) and in the current residence (water damage: 1.33; damp stains: 1.34; mold spots: 1.32; and windows pane condensation: 1.31). Parental smoking, pet-keeping, and incense-burning had no significant associations with childhood eczema. Similar associations were found for eczema in the last year before the survey. Families with sick children likely changed lifestyle behaviors and dietary habits.

CONCLUSIONS

Childhood eczema could be influenced by many household environmental and non-environmental factors. Exposures during early lifetime likely have greater impact on childhood eczema than current exposures. Associations of lifestyle behaviors and dietary habits with childhood eczema could be modified by family avoidance behaviors.

Household indoor air quality and its associations with childhood asthma in Shanghai, China: On-site inspected methods and preliminary results

Few studies were conducted for associations of home environment with childhood health by on-site inspection in China. During 2013-2014, we conducted a case-control study with home inspection among 454 children (186 asthma children and 268 non-asthma children) in Shanghai, China. In this paper, we detailedly described the inspected methods and analyzed the preliminarily collected data. Except in winter, most residences meet the national standard for indoor temperature and relative humidity. Most living rooms had ≤1000ppm CO₂, whereas over half of the child's bedrooms had slightly >1000ppm CO₂ during night. Most residences had notably lower than 2500cfu/m³ airborne culturable fungi and ≤100μg/m³ formaldehyde. More than 70% of the child's bedrooms had ≤75μg/m³ PM_2.5 and ≤150μg/m³ PM₁₀. Indoor and outdoor concentrations of particulate matters had strong linear correlations (r=0.891-0.922; p-value <0.001). Most differences between cases and controls were not significant with respect to CO₂, culturable fungi, formaldehyde, and particulate matters. Before and after adjusted for potential confounders, indoor averaged concentration of CO₂ and particulate matters generally had negative associations with childhood history of doctor-diagnosed asthma in spring, summer, and autumn. Only in winter, indoor CO₂ concentration was significantly associated with the increased odds of childhood asthma. Our results indicated that air quality among most residences in Shanghai could meet the national standard for indoor air quality in warm seasons; but household air quality and ventilation status in winter should be greatly improved. We suspected that those "unexpected" negative associations could exist due to changes in lifestyle behaviors regarding indoor air quality after the child being diagnosed asthma by a doctor.

Poor housing conditions in association with child health in a disadvantaged immigrant population: a cross-sectional study in Rosengård, Malmö, Sweden

OBJECTIVES

To describe the home environment in terms of housing conditions and their association with child health in a disadvantaged immigrant population.

DESIGN

A cross-sectional observational study.

SETTING

Enrolment took place during 2010-2011 in Rosengård, Malmö, Sweden.

PARTICIPANTS

Children aged 0-13 years in 2 study neighbourhoods were recruited from local health records and from schools. 359 children participated, with a participation rate of 40%. Data on health, lifestyle and apartment characteristics from questionnaire-led interviews with the mothers of the children were obtained together with data from home inspections carried out by trained health communicators.

OUTCOME MEASURES

Logistic regression analysis was used to estimate ORs for various health outcomes, adjusted for demographic information and lifestyle factors.

RESULTS

The housing conditions were very poor, especially in one of the study neighbourhoods where 67% of the apartments had been sanitised of cockroaches, 27% were infested with cockroaches and 40% had a visible mould. The association between housing conditions and health was mostly inconclusive, but there were statistically significant associations between current asthma and dampness (OR=4.1, 95% CI 1.7 to 9.9), between asthma medication and dampness (OR=2.8, 95% CI 1.2 to 6.4), and between mould and headache (OR=4.2, 95% CI 1.2 to 14.8). The presence of cockroaches was associated with emergency care visits, with colds, with headache and with difficulty falling asleep, and worse general health was associated with mould and presence of cockroaches.

CONCLUSIONS

The associations between dampness and asthma, and the association between mould and headache, are in line with current knowledge. The presence of cockroaches seemed to be associated with various outcomes, including those related to mental well-being, which is less described in the literature. The results of the present study are hypothesis generating and provide strong incentives for future studies in this study population.

Home environment, lifestyles behaviors, and rhinitis in childhood

The prevalence of children allergic rhinitis has been increasing in China and associated factors still are not clear. In the present paper, we selected 13,335 parent-reported questionnaires of 4-6 years-old children, in a cross-sectional study from April 2011 to April 2012 in Shanghai city, and investigated associations of various factors with parent-reported allergic rhinitis (doctor-diagnosed) and rhinitis symptoms in childhood. After adjusted by age, sex, family history of atopy, and respondent of questionnaire, we find that no siblings, mother in older age during pregnancy, shorter breastfeeding, using antibiotics in the first year, and home dampness-related exposures, had significant associations with increased prevalence of the studied diseases. Location, type, building area, decoration materials and construction period of the residence, also had significant associations with these diseases. Current parental smoking and pet-keeping had no significant associations with the studied diseases. Incense-burning and using mosquito coils had significant associations with reduced risk of allergic rhinitis and with increased risk of rhinitis symptoms. Using air cleaner and cleaning the residence in high frequency had associations with increased risk, but eating fast food and ice cream often had associations with the reduced risk, of the studied diseases. Families with children being diagnosed allergic rhinitis likely change their lifestyle behaviors. In conclusion, childhood rhinitis could be influenced by heredity and many "environmental exposures". Avoidance behaviors and reverse causation in parental smoking, pet-keeping, and dietary habits for childhood rhinitis should be carefully considered.

Home dampness, childhood asthma, hay fever, and airway symptoms in Shanghai, China: associations, dose-response relationships, and lifestyle's influences

Numerous studies of associations between dampness and respiratory diseases have been conducted, but their implications remain inconclusive. In this study of 13,335 parent-reported questionnaires (response rate: 85.3%), we analyzed associations between home dampness and asthma and related symptoms in 4- to 6-year-old children in a cross-sectional study of Shanghai. Indicators of home dampness were strongly and significantly associated with dry cough, wheeze, and rhinitis symptoms. In the current residence, children with visible mold spots (VMS) exposure had 32% higher risk of asthma (adjusted OR, 95% CI: 1.32, 1.07-1.64); damp clothing and/or bedding (frequently) was strongly associated with dry cough (1.78, 1.37-2.30); condensation on windows was strongly associated with hay fever (1.60, 1.27-2.01). In the early-life residence, VMS or damp stains (frequently) were strongly associated with dry cough (2.20, 1.55-3.11) and rhinitis ever (1.57, 1.11-2.21). Associations between dampness and diseases among children with or without family history of atopy were similar. The total number of dampness indicators had strong dose-response relationships with investigated health outcomes. Actions, including opening windows of the child's room at night and cleaning the child's room frequently, could potentially mitigate 25% of home VMS, thereby preventing more than 1.5% of attributable risk of the studied symptoms.