Emerging concern on air pollution and health: Trade-off between air pollution exposure and physical activity.

Air pollution is a major contributor to the global disease burden, especially affecting respiratory and cardiovascular health. However, physical activity is associated with improved lung function, a slower decline in lung function, and lower mortality. The public is more likely to be exposed to air pollution during outdoor physical activity. However, studies on how long-term and short-term exposure to air pollution interacts with physical activity yield inconsistent results, and the thresholds for air pollution and physical activity remain unclear. Thus, more studies are needed to provide sufficient evidence to guide the public to safely engage in outdoor physical activity when exposed to air pollution.

[Characteristics and Identification Priority Source of Heavy Metals Pollution in Farmland Soils in the Yellow River Basin].

Assessments of the soil environmental quality of farmland and pollution source apportionment are the foundation for ensuring national food security and agricultural sustainable development, as well as an important prerequisite for the pursuit to keep our lands clean. This study evaluated the characteristics of heavy metal pollution in farmland soils in the Yellow River Basin from 2000 to 2023, based on the data of heavy metal contents including As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn, using the geo-accumulation index method. Source apportionment was conducted by employing a positive matrix factorization (PMF) model. The probabilistic health risks were evaluated by coupling Monte Carlo simulation with a human health risk assessment model, and priority pollution sources and elements were identified. The results showed that:① the average content of all heavy metals in farmland soils within the study area was lower than the screening values specified in the soil environment quality risk control standard for soil contamination of agriculture land (GB 15618-2018) (pH>7.5). However, the contents of Cd, As, and Zn in the samples exceeded their screening values, with percentages of 21.69%, 5.56%, and 1.23%, respectively, with Cd having the highest rate of exceedance. ② Hg and Cd were moderately polluted, Cu and Pb were slightly polluted, and the other elements were not polluted. ③ The main sources of heavy metals in farmland soil were traffic-industrial sources, natural-agricultural sources, industrial-natural sources, and agricultural-industrial sources, with contribution rates of 37.04%, 26.69%, 21.72%, and 14.55%, respectively. ④ Heavy metals in farmland soil posed carcinogenic health risks to adults and children but did not have non-carcinogenic risks; As and Cd were priority control elements for human health risks, and industrial-natural sources and agricultural-industrial sources were priority control sources in the study area.

Domestic dogs as sentinels of children lead exposure: Multi-pathway identification and source apportionment based on isotope technique.

Environmental lead exposure poses risks to children' health, thus exposure sources and pathways identification remain important concern and research scope. Due to sharing the same environment, domestic animals, especially dogs, have been used as useful sentinels to identify human lead exposure. However, more evidence is needed on whether domestic dogs could be used to identify the lead exposure pathways and sources of children. Thus, this study investigated the dietary habits, behaviors, and household environment of children and dogs in a typical coal-fired area in China. The lead levels and lead isotope ratios (Acronym: LIRs, expressed as 208Pb/206Pb and 207Pb/206Pb) in dogs' and children's blood, as well as in environmental media (food, PM2.5, indoor/outdoor dust, drinking water and soil) were measured to explore the predominant lead pollution sources and exposure pathways of children. The results showed that the LIRs of children's blood (208Pb/206Pb = 2.0703 ± 0.0076, 207Pb/206Pb = 0.8501 ± 0.0052) were similar to those of dogs' blood (208Pb/206Pb = 2.0696 ± 0.0085, 207Pb/206Pb = 0.8499 ± 0.0052), as well as similar to the LIRs of environmental media, i.e. children's food (208Pb/206Pb = 2.0731 ± 0.0057, 207Pb/206Pb = 0.8491 ± 0.0036) and coal (208Pb/206Pb = 2.0683 ± 0.017, 207Pb/206Pb = 0.8515 ± 0.01). Children and dogs had similar lead exposure pathways, but the contributions of each exposure pathway were different, i.e., 83.1% vs. 76.9% for children and dogs via food ingestion, 1.4% vs. 5.6% via particulate matter exposure, and 15.5% vs. 17.5% via household dust exposure, respectively. The contribution of food via ingestion to lead exposure remains dominant, and coal combustion is a main lead exposure source for children and domestic dogs.

Environmental and Behavioral Factors in Association with Lung Function Impairment in Children Living in Wuhan, China.

Children's lung function is a significant predictor of health status throughout their lifetime. This study aims to identify the prevalence of impaired lung function in children and the potential influencing factors in elementary school children of Wuhan, China. Children of 6−12 years old were enrolled from elementary schools in Wuhan, China, in 2018, on the basis of a cross-sectional study design. Information on personal behavior patterns and household characteristics, as well as parental factors, was collected based on a questionnaire survey. Spirometry was used to measure fifteen lung function indicators. Logistic regression models were used to estimate odds ratios of prevalence of impaired lung function with regard to socioeconomic, personal behavior patterns, household, and parental factors, respectively. Four lung function indicators such as FET and EVC in urban children had higher values than in the suburban children after adjusting for confounders (p < 0.05). A higher prevalence of impaired lung function (FEV6, FEV3, EVC, and VC) was found in the children from the rural area than in those from the urban area. A sex difference in FET impairment was observed, however, no significant difference in impairment in other lung function indicators were found between girls and boys. The elevated height and weight of the children was significantly associated with an increased and decreased prevalence of impaired lung function, respectively, particularly both for FEV6, FEV3, FIVC, and FIV1. Opening windows for a longer time in summer was significantly associated with a lower prevalence of impaired FEF25 and MVV, and an extended time of opening windows in winter was significantly associated with a lower prevalence of impaired FEV6. While, opening windows for a longer time in autumn was significantly associated with higher prevalence of impaired FEV6 and FEV1/VC. Home renovations, doing physical exercise for more than 30 min per day, air pollution exposure during commuting, sleeping in own rooms, height stunting, and preterm birth were significantly associated with an increased risk of impaired lung function. Breastfeeding, having a father with a white-collar profession and with a higher education level were positively associated with the lower prevalence of impaired lung function. Impaired lung function is commonly found in school children in Wuhan, nowadays. Breastfeeding, opening windows long-term in summer and winter, higher socioeconomics, and an urban living environment were protective factors for impaired lung function. However, opening windows long-term and using air conditioning short-term in autumn, as well as home renovations, doing physical exercise for more than 30 min per day, preterm birth, height stunting, and air pollution exposure during commuting were regarded as significant risk factors for impaired lung function. Promoting breastfeeding, lengthening window opening times in winter and summer, and controlling household renovation and air pollution exposure during commuting are recommended to reduce the risk of impaired lung function in children in Wuhan.

Sentinel animals for monitoring the environmental lead exposure: combination of traditional review and visualization analysis.

In nature, certain animals share a common living environment with humans, thus these animals have become biomonitors of health effects related to various environmental exposures. As one of the most toxic environmental chemicals, lead (Pb) can cause detriment health effects to animals, plants, and even humans through different exposure pathways such as atmosphere, soil, food, water, and dust, etc. Sentinel animals played an "indicative" role in the researches of environmental pollution monitoring and human health. In order to comprehend the usage of sentinel animals in the indication of environmental Pb pollution and human Pb exposure completely, a combination of traditional review and visualization analysis based on CiteSpace literature was used to review earlier researches in this study. In the first instance, present researches on exposure sources and exposure pathways of Pb were summarized briefly, and then the studies using sentinel animals to monitor environmental heavy metal pollution and human health were combed. Finally, visualization software CiteSpace 5.8.R3 was used to explore and analyze the hotspots and frontiers of lead exposure and sentinel animals researches at home and abroad. The results showed that certain mammals were good indicators for human lead exposure. Sentinel animals had been widely used to monitor the ecological environment and human lead exposure. Among them, the blood lead levels of small mammals, particularly for domestic dogs and cats, had a significant correlation with the blood lead levels of human living in the same environment. It indicated that certain biological indicators in animals can be used as surrogates to monitor human body exposure to heavy metals. This study also explored the challenges and perspectives that may be faced in sentinel animal research, in order to provide a certain theoretical basis and train of thought guidance for future research.

Traffic related activity pattern of Chinese adults: a nation-wide population based survey.

BACKGROUND: Traffic-related air pollutants lead to increased risks of many diseases. Understanding travel patterns and influencing factors are important for mitigating traffic exposures. However, there is a lack of national large-scale research. OBJECTIVE: This study aimed to evaluate the daily travel patterns of Chinese adults and provide basic data for traffic exposure and health risk research. METHODS: We conducted the first nation-wide survey of travel patterns of adults (aged 18 and above) in China during 2011-2012. We conducted a cross-sectional study based on a nationally representative sample of 91, 121 adults from 31 provinces in China. We characterized typical travel patterns by cluster analysis and identified the associated factors of each pattern using multiple logistic regression and generalized linear regression models. RESULTS: We found 115 typical daily travel patterns of Chinese adults and the top 11 accounted for 94% of the population. The interaction of age, urban and rural areas, income levels, gender, educational levels, city population and temperature affect people's choice of travel patterns. The average travel time of Chinese adults is 45 ± 40 min/day, with the longest travel time by the combination of walking and car (70 min/day). Gender has the largest effect on travel time (B = -8.94, 95% CI: -8.95, -8.93), followed by city GDP (B = -4.23, 95% CI: -4.23, -4.22), urban and rural areas (B = -3.62, 95% CI: -3.63, -3.61), age (B = -2.21, 95% CI: -2.21, -2.2), educational levels (B = -1.53, 95% CI: -1.53, -1.52), city area (B = -1.4, 95% CI: -1.4, -1.39) and temperature (B = 1.21, 95% CI: 1.2, 1.21). SIGNIFICANCE: This study was the first nation-wide study on traffic activity patterns in China, which provides basic data for traffic exposure and health risk research and provides the basis for the state to formulate transportation-related policies.

Has the Risk of Outpatient Visits for Allergic Rhinitis, Related to Short-Term Exposure to Air Pollution, Changed over the Past Years in Beijing, China?

A number of studies have found associations between the short-term exposure to ambient air pollution and hospital admissions. However, little is known about the temporal variations in ambient air pollution associated with health exposure, especially in China. We evaluated whether the risks of allergic rhinitis (AR) outpatient visits from short-term exposure to air pollution varied over time (2014-2020) in Beijing, China. A quasi-Poisson generalized additive model was used to evaluate the relative risks (RRs) and 95% confidence intervals (CIs) associated with the pollutant concentrations during the entire study period and three specific periods. We also analyzed the temporal variations of the period-specific associations and tested the trend of change using the Mann-Kendall test. The concentration-response relationships for the specific periods were further investigated. The RRs (95%CI) for an interquartile range (IQR) increased in PM10 (70 µg/m3) and CO (0.5 mg/m3) decreased from period 1 to period 3. However, The RRs (95%CI) of PM2.5 (55 µg/m3), SO2 (7 µg/m3) and NO2 (27 µg/m3) increased from 1.015 (0.978, 1.054), 1.027 (1.009, 1.044) and 1.086 (1.037, 1.137) in period 1 to 1.069 (1.005, 1.135), 1.074 (1.003, 1.149) and 1.214 (1.149, 1.282) in period 3, respectively. A statistically significant temporal change and the stable effects were observed between the NO2 exposure and AR visits over time. Despite a substantial reduction in ambient air pollution, the short-term effects on AR outpatient visits remained significant. Our findings provide a rationale for continued air pollution control efforts in the future to minimize air pollution and to protect the public.

Source apportionment based on lead isotope ratios: Could domestic dog's blood lead be used to identify the level and sources of lead pollution in children?

Domestic dogs have been proved to be used as "sentinel organisms" to monitor human lead exposure. However, whether dogs' blood can be used to identify the levels and pollution source of children's lead exposure still needs evidence. To evaluate the potential use of domestic dogs' blood lead as an indicator of lead exposure levels and pollution source of children, accompanying with potential environmental media samples, lead concentrations and isotope ratios (expressed as 207Pb/206Pb, 208Pb/206Pb) in blood were investigated and compared between children and dogs, who came from a Pb-Zn smelter area, a coal fired area and a control area without industrial activity. The results showed that there were significant correlations in blood lead levels (BLLs) between children and dogs in the study areas (p < 0.01). The lead isotope ratios (LIRs) in blood of children and dogs were disparate among the three areas, however, the LIRs of dogs were quite correlated with those of children in each area (p < 0.01). With the comparison of LIRs between potential pollution sources (slag, ore, coal, paint) and blood samples, the identified lead sources based on dogs' blood were found to be coincident with those based on children's blood. Ore smelting and coal combustion were the main sources of lead exposure for the dogs and children in the smelting area, and coal combustion was the predominant source for the children and dogs living in the coal burning area and control area. The results showed that dogs' BLLs might be used to estimate children's BLLs, and blood LIRs measurements of dogs' could be used as an alternative for identifying the sources of children's lead exposure. This study further provided relevant evidence for dogs to be sentinels exposed to human lead exposure and an alternative method for source apportionment of children's lead exposure.

Chemical constituents of ambient fine particulate matter and obesity among school-aged children: A representative national study in China.

BACKGROUND: Studies show that fine particulate matter (PM2.5) contributes to childhood obesity. However, evidence on the effects of its constituents on obesity has not been explored. METHODS: Using multistage stratified cluster sampling, we enrolled 41,439 school-age children (aged 6-17 years) from a representative nationwide survey of 30 provinces in China (mean age ± standard deviation: 12.0 ± 3.3 years). Weight and height were measured using a physician beam scale with a height rod, and covariates were determined using a standard questionnaire. The concentration of PM2.5 chemical constituents was estimated by a chemical transport (GEOS-Chem) model using input satellite data and ground-based observations. The constituents included black carbon, ammonium, nitrate, organic matter, sulfate, and soil dust. Generalized linear models were used to estimate the association between the chemical constituents of PM2.5 and obesity. RESULTS: A positive association between the constituents of PM2.5 and obesity were observed. Children were more susceptible to black carbon than other species. A 1-µg/m3 increase in black carbon led to a 0.079 (95 % confidence interval [CI]:0.028, 0.130)-kg/m2 increase in body mass index (BMI). This also increased the odds of being obese and overweight to 1.174 (95 % CI: 1.111, 1.240) and 1.165 (95 % CI: 1.116, 1.216), respectively. Stratified analyses showed that the effects were stronger in girls and older children, as well as in urban and Northeast regions. The effect of the PM2.5 constituents on obese and overweight children from urban areas significantly interacted with that of rural areas. CONCLUSIONS: The PM2.5 constituents were associated with an increased BMI and childhood obesity. Further studies are warranted to validate these results and clarify their potential mechanisms. We suggest focusing on black carbon and Northeast regions.

Household mold exposure in association with childhood asthma and allergic rhinitis in a northwestern city and a southern city of China.

Background: The prevalence of asthma and allergic diseases has increased rapidly in Chinese cities over the past decades. Few studies have examined the potential role of household mold in asthma and allergies in Chinese cities. Methods: A cross-sectional survey in 4,691 school-age children was performed in Lanzhou and Wuhan. The two cities represent distinct climate conditions, as Lanzhou, located in northwestern China, has dry and cold winter and relatively cool summer whereas Wuhan, located in central-southern China, has hot and humid summer and mild winter temperatures. Two schools were randomly selected from a suburb and an urban area of each city, respectively. Data were collected using a modified Chinese version of the American Thoracic Society (ATS) standard respiratory health questionnaire for children, regarding asthma, substance allergy, allergic rhinitis, presence of mold in residence, and household characteristics. Logistic regression models were applied to identify the odds ratios of childhood asthma and allergies with regard to mold. Results: The prevalence rates of asthma, substance allergy, allergic rhinitis, and mold, were all higher in Wuhan than in Lanzhou. We observed significant associations of household mold with increased prevalence for both asthma [odds ratio (OR) =2.399, 95% confidence interval (95% CI): 1.309-4.398], substance allergy (OR =1.729, 95% CI: 1.282-2.332) and allergic rhinitis (OR =1.969, 95% CI: 1.491-2.600), with spatial heterogeneity across urban versus suburban schools. The mold effect was modified by age group and breast-feeding status. Conclusions: Across two climatically distinct cities, household mold exposure was significantly associated with an increased risk for asthma and allergies. Younger children and children from the suburbs were more likely to be affected by mold. Whether breastfeeding enhanced or weakened the mold effects were inconsistent across the cities and across the health outcomes.

Effects of physical activity intensity on adulthood obesity as a function of long-term exposure to ambient PM2.5: Observations from a Chinese nationwide representative sample.

Long-term exposure to PM2.5 has been associated with increased obesity risk, while physical activity (PA) is a suggested protective factor. This raises a dilemma whether the increased dose of PM2.5 due to PA-intensified ventilation would offset the benefits of PA. Using a national representative sample, we aim to (1) ascertain inclusive findings of the association between PA and obesity, and (2) examine whether PM2.5 exposure modifies the PA-obesity relationship. We recruited 91,121 Chinese adults from 31 provinces using a multi-stage stratified-clustering random sampling method. PM2.5 was estimated using a validated machine learning method with a spatial resolution of 0.1° × 0.1°. PA intensity was calculated as metabolic equivalent (MET)-hour/week by summing all activities. Body weight, height, and waist circumference (WC) were measured after overnight fasting. Obesity-related traits included continuous outcomes (Body mass index [BMI], WC, and waist-to-height ratio (WHtR)) and binomial outcomes (general obesity, abdominal obesity, and WHtR obesity). Generalized linear regression models were used to estimate the interaction effects between PM2.5 and PA on obesity, controlling for covariates. The results indicated that each IQR increase in PA was associated with 0.078 (95% CI: -0.096 to -0.061) kg/m2, 0.342 (-0.389 to -0.294) cm, and 0.0022 (-0.0025 to -0.0019) decrease in BMI, WC, and WHtR, respectively. The joint association showed that benefits of PA on obesity were attenuated as PM2.5 increased. Risk of abdominal obesity decreased 11.3% (OR = 0.887, 95% CI: 0.866, 0.908) per IQR increase in PA among the low-PM2.5 (≤55.9 µg/m3) exposure group, but only 5.5% (OR = 0.945, 95% CI: 0.930, 0.960) among the high-PM2.5 (>55.9 µg/m3) exposure group. We concluded the increase in PA intensity was significantly associated with lower risk of obesity in adults living across mainland China, where annual level of PM2.5 were mostly exceeding the standard. Reducing PM2.5 exposure would enhance the PA benefits as a risk reduction strategy.

Distributions and determinants of time spent outdoors among school-age children in China.

BACKGROUND: The outdoor time is a key factor that determines children's exposure to environmental contaminants. Meanwhile, children reap numerous physical and mental health benefits from playing outdoors. OBJECTIVE: This study aimed to characterize the distributions and identify determinants of the time spent outdoors among school-age children in China. METHODS: The study recruited 41,439 children aged 6-17 years in Mainland China using a multi-stage cluster random sampling method. This sample was nationally representative with sample weights created to account for the complex survey design. Information on time-activity patterns were collected with a standard questionnaire through face-to-face interviews. Frequency distributions of time outdoors were created by age group, gender, region, and other sociodemographic factors with sample weights. The key factors influencing time outdoors were identified using multivariable linear regression models. RESULTS: The grand mean (±standard deviation) time outdoors was 101 ± 51 min/day for all the study participants, 22.3% having <60 min/day. Children spent longer time outdoors in warm seasons and on weekends. Children's outdoor time was significantly influenced by gender, age, urbanicity, region, annual total household expenditure, building environment, and meteorological conditions (annual mean temperature, sunshine time, and precipitation). Girls, 15-17 year old, and urban children had 6 min/day, 8 min/day, and 13 min/day less outdoor time than boys, 6-8 year old, and rural children, respectively. Most significantly, urban girls and high school students had the shortest outdoor time. The cement ground was the most important type of ground for children playing outside. SIGNIFICANCE: This was the first national-scale study that characterized the time outdoors and where is it spent among school-age children in China. It revealed that one-fifth of Chinese children spent less than one hour outdoors every day, and urban girls had particular "indoor tendencies". The findings provide bases for future interventions and guidelines aimed at promoting children's physical activities.

Association between exposure to air pollution and risk of allergic rhinitis: A systematic review and meta-analysis.

BACKGROUND: Allergic rhinitis (AR) is one of the most common allergic diseases in the world, and usually persists throughout the activity. Epidemiological studies have shown a positive association between air pollution and allergic rhinitis. However, we could not find any meta-analysis of the risk of air pollutants (PM2.5, PM10, NO2, SO2, O3 and CO) on the prevalence of AR in people of all ages. OBJECTIVES: Carry out a meta-analysis on the results of recent studies (up to 2020) to present valid information about exposure to air pollution and risk of prevalence of AR. METHODS: We systematically searched three databases for studies up to December 17, 2020, including air pollution and AR. Random effect models were conducted to estimate the pooled odds ratios (ORs) and 95% confidence intervals (95% CIs). Subgroup analysis, funnel plot, Egger's test, and the trim-and-fill method were also conducted. RESULTS: Thirty-five studies across 12 countries, including a total of 453,470 participants, were included. The OR per 10 µg/m3 increase of pollutants was 1.13 (1.04-1.22) for PM10 and 1.12 (1.05-1.20) for PM2.5. The OR per 10 µg/m3 increment of gaseous pollutants were 1.13 (1.07-1.20) for NO2, 1.13 (1.04-1.22) for SO2 and 1.07 (1.01-1.12) for O3. No significant association was observed between CO and AR. Children or adolescents are more sensitive to air pollution than adults. The effects of PM10 and SO2 were significantly stronger in Europe than Asia. The effects of air pollutants were more significant and higher in developing countries than in developed countries, except for PM10. A significant difference of subgroup test was found between developed and developing countries of NO2. CONCLUSION: This meta-analysis showed a positive association between air pollution and the prevalence of allergic rhinitis, and identified geographic area and economic level as the potential modifiers for the association.

A comprehensive analysis on source-distribution-bioaccumulation-exposure risk of metal(loid)s in various vegetables in peri-urban areas of Shenzhen, China.

The health risk induced by metal(loid)s in crops are becoming increasingly serious. In this study, eight major vegetables and rhizosphere soils were collected in a peri-urban area with intense electronic information manufacturing activities. The source, distribution and bioaccumulation of six typical metal(loid)s in different vegetable species were analyzed, and exposure risk through vegetable ingestion was estimated. Results showed that vegetables and agricultural soils in the study area suffered from serious metal(loid)s pollution, especially for Cd and Pb. The bioaccumulation capacity differed greatly among individual metal(loid)s and vegetable categories. In general, the highest transfer factors (TF) for Cd, Pb, and As were found in leafy vegetables, while leguminous vegetables had the highest TF of Cu and Zn and root vegetables had the highest TF for Cr. Significant correlations were found between concentrations in vegetables and rhizosphere soils for most metal(loid)s, the exceptions being Pb and Zn. The enrichment of Pb, Cd, Cr and As was mainly attributed to electronic information manufacturing activities, while the enrichment of Zn, Cu and Cd was associated with the application of commercial fertilizers and pesticides. The health risk associated with vegetable intake decreased in the order of leafy > fruit > leguminous > root vegetables. Leafy vegetables were identified as the category with the highest risk, with the mean risk value of 1.26. Cd was the major risk element for leafy vegetables. The non-carcinogenic risks estimated for leguminous and root vegetables were under the acceptable level. In conclusion, special attention should be paid to the health risks of toxic metal(loid)s in leafy vegetables in peri-urban areas with intense electronic information manufacturing activities. In order to minimize health risk, it is necessary to identify low-risk crops based on a comprehensive consideration of the metal(loid)s' pollution characteristics, transfer factors and local people's consumption behaviors.

Health risk assessment of As due to rice ingestion based on iAs distribution and actual consumption patterns for the residents in Beijing: a cross-sectional study.

As a well-known human carcinogen, arsenic (As) could pose various detrimental health effects to humans mainly through the exposure pathway of food ingestion. In comparison with other foods, rice can accumulate more arsenic due to its tissue specificity. Thus, it is of great significance to assess the health risk of As due to rice ingestion. However, the study on risk assessment from exposure to As in rice is still in an early stage and lack accuracy to date. In this study, after obtaining the rice exposure behavior patterns based on a questionnaire survey, a total of 160 rice samples, which consisted of 4 types (i.e., japonica, indica, glutinous and brown rice), rice from 4 areas and consumed by most of the population in Beijing, were collected. On the basis of the actual intake rate and the species weighted average concentration of consumed rice, average daily exposure dose and health risks of inorganic As (iAs) from rice ingestion were assessed for the population among different genders and ages in Beijing. The results show that japonica rice and rice from Northeast China had higher As content, with the same value of 0.064 mg kg-1. And, they were the most popular rice consumed by people, with the intake rates of 75.50 g d-1, and 67.91 g d-1, respectively. The proportion of iAs to total As (tAs) was 58.34%, with a range of 43.18-71.88%. The average daily dose of iAs for the population was 1.15 × 10-4, which mainly came from japonica rice and the rice from Northeast China ingestion. In comparison with the acceptable non-cancer risk, which had a HQ value of 0.38, the carcinogenic risk of the population in Beijing was 1.73 × 10-4 on average. Furthermore, males had higher carcinogenic risk (1.88 × 10-4) than females (1.62 × 10-4), and the people in the age of 45-55 suffered from the highest carcinogenic risk (2.22 × 10-4), which mainly was attributed to the japonica rice and the rice from Northeast China. This study strengthened that appropriate dietary patterns should be paid more attention in order to control the health risk due to As exposure.

Non-negligible contributions to human health from increased household air pollution exposure during the COVID-19 lockdown in China.

BACKGROUND: Ambient and household air pollution are found to lead to premature deaths from all-cause or cause-specific death. The national lockdown measures in China during COVID-19 were found to lead to abrupt changes in ambient surface air quality, but indoor air quality changes were neglected. In this study, we aim to investigate the impacts of lockdown measures on both ambient and household air pollution as well as the short-term health effects of air pollution changes. METHODS: In this study, an up-to-date emission inventory from January to March 2020 in China was developed based on air quality observations in combination with emission-concentration response functions derived from chemical transport modeling. These emission inventories, together with the emissions data from 2017 to 2019, were fed into the state-of-the-art regional chemistry transport model to simulate the air quality in the North China Plain. A hypothetical scenario assuming no lockdown effects in 2020 was also performed to determine the effects of the lockdown on air quality in 2020. A difference-to-difference approach was adopted to isolate the effects on air quality due to meteorological conditions and long-term decreasing emission trends by comparing the PM2.5 changes during lockdown to those before lockdown in 2020 and in previous years (2017-2019). The short-term premature mortality changes from both ambient and household PM2.5 changes were quantified based on two recent epidemiological studies, with uncertainty of urban and rural population migration considerations. FINDINGS: The national lockdown measures during COVID-19 led to a reduction of 5.1 µg m-3 in ambient PM2.5 across the North China Plain (NCP) from January 25th to March 5th compared with the hypothetical simulation with no lockdown measures. However, a difference-to-difference method showed that the daily domain average PM2.5 in the NCP decreased by 9.7 µg m-3 between lockdown periods before lockdown in 2020, while it decreased by 7.9 µg m-3 during the same periods for the previous three-year average from 2017 to 2019, demonstrating that lockdown measures may only have caused a 1.8 µg m-3 decrease in the NCP. We then found that the integrated population-weighted PM2.5, including both ambient and indoor PM2.5 exposure, increased by 5.1 µg m-3 during the lockdown periods compared to the hypothetical scenario, leading to additional premature deaths of 609 (95% CI: 415-775) to 2,860 (95% CI: 1,436-4,273) in the short term, depending on the relative risk chosen from the epidemiological studies. INTERPRETATION: Our study indicates that lockdown measures in China led to abrupt reductions in ambient PM2.5 concentration but also led to significant increases in indoor PM2.5 exposure due to confined indoor activities and increased usages of household fuel for cooking and heating. We estimated that hundreds of premature deaths were added as a combination of decreased ambient PM2.5 and increased household PM2.5. Our findings suggest that the reduction in ambient PM2.5 was negated by increased exposure to household air pollution, resulting in an overall increase in integrated population weighted exposure. Although lockdown measures were instrumental in reducing the exposure to pollution concentration in cities, rural areas bore the brunt, mainly due to the use of dirty solid fuels, increased population density due to the large-scale migration of people from urban to rural areas during the Chinese New Year and long exposure time to HAP due to restrictions in outdoor movement.

Source identification of pollution and health risks to metals in household indoor and outdoor dust: A cross-sectional study in a typical mining town, China.

Dust is regarded as an important pathway of heavy metal(loid)s to the human body. Health risks posed by metal(loid)s from household dust are of particular concern. However, the contamination and sources of heavy metal(loid)s in household dust environments, as well as source identification of health risks related to heavy metal(loid)s from household dust for vulnerable populations such as children, have not been thoroughly studied in China, particularly for the areas involved with industrial activities such as ore mining. Thus, a cross-sectional study was conducted in a rural area famous for Pb/Zn ore mining, to assess the pollution sources and health risks of heavy metal(loid)s from household indoor and outdoor dust and to identify the contribution of household dust to the health risks for children. The results indicated that household environment was heavily contaminated by metal(loid)s, which were mainly attributed to mining activity. Meanwhile, the indoor/outdoor ratio and the redundancy analysis indicated that there were other pollution sources in indoor environments such as coal combustion, materials for interior building and decoration. Vapor inhalation was the main exposure pathway for Hg, while ingestion was the predominant pathway for other metal(loid)s. Although the cancer risks were relatively low, the HIt from household indoor and outdoor dust (2.19) was about twice the acceptable limit (1) and was primarily from Pb (64.52%) and As (23.42%). Outdoor dust was a larger contributor to the HI of Sb, As, Cr, Cd, Zn and Pb, which accounted for 51.37%, 58.63%, 52.14%, 59.66%, 52.87% and 64.47%, respectively, and the HIt was mainly from outdoor dust (60.76%). These results indicated that non-cancer health risks were largely from outdoor dust exposure, and strengthened the notion that concern should be given to the potential health risks from metal(loid)s in household dust both originating from mining activity and indoor environmental sources.

The effects of indoor and outdoor air pollution on the prevalence of adults' respiratory diseases in four Chinese cities: a comparison between 2017-2018 and 1993-1996.

BACKGROUND: Over the past decades, both ambient and household air pollution have changed in several aspects, including the emission sources and the concentrations of pollutants, in many Chinese cities. It is unknown whether these changes are associated with changes in health conditions, especially given changes in other factors due to rapid economic growth. METHODS: Two cross-sectional surveys were conducted in two periods spanning more than twenty years (1993-1996 vs. 2017-2018) in four Chinese cities of Chongqing, Wuhan, Lanzhou, and Guangzhou. Data were collected regarding adults' respiratory disease, smoking status, education, occupation, and household characteristics. Ambient air pollution data were obtained for each study. We first used logistic regression models to construct the district-specific adjusted disease prevalences. In the second stage, first-difference regression models were employed to examine whether the change in respiratory diseases prevalences was associated with the change in outdoor air pollution and indoor air pollution surrogates. RESULTS: A total of 7,557 and 9,974 households were participating in Period 1 (1993-1996) and Period 2 (2017-2018), respectively. Compared to Period 1, we found substantial reductions in the ambient air pollution concentrations, and a suggestive improvement in cooking-related indoor air pollution in Period 2. We observed decreases in the district-specific covariate-adjusted prevalences of both asthma and chronic bronchitis among participants, with an average reduction of 3.6% (range: 0.0% to 24.3%). From Period 1 to Period 2, one percent decrease in the proportion of cooking with coal was associated with a 19.0% (95% CI, 0.96-37.04%) decrease in the prevalence of males' chronic bronchitis and a 1.86% (0.69-3.04%) increase in the prevalence of females' asthma. Little evidence was observed regarding the potential health benefits associated with the decreases in ambient air pollution levels. CONCLUSIONS: The substantial reduction in household use of coal for cooking might be an important contributor to the decrease in adults' respiratory disease prevalence from 1993-1996 to 2017-2019 in four Chinese cities. Changes in this indoor air pollution source, along with other risk factors for respiratory diseases, may have masked respiratory health benefits associated with reductions in outdoor air pollution levels.

Children's lung function in relation to changes in socioeconomic, nutritional, and household factors over 20 years in Lanzhou.

BACKGROUND: Lanzhou has experienced rapid urbanization, leading to changes in socioeconomic, nutritional, and household factors. These changes may affect children's lung function. METHODS: Two cross-sectional studies of school-age children (6-13 years of age) from the urban (Chengguan) (Period 1 in 1996 with n=390; Period 2 in 2017 with n=192) and the suburban (Xigu) (Period 1 n=344; Period 2 n=492) district were conducted. Demographic information, household factors, and nutrition status were obtained via a questionnaire survey. Forced vital capacity (FVC) and forced expiratory volume in the first second (FEV1) were measured in each period. Student's t-test analysis of variance was used to assess the differences in FVC and FEV1 between Periods 1 and 2. Generalized linear models were used to analyze the associations between questionnaire derived factors and lung function. Analyses were done separately for girls and boys. RESULTS: Children had significantly lower mean FEV1 and FVC measures in Period 2 than in Period 1. This reduction was greater in children living in the urban area than those living in the suburban area. Obese children had significantly lower lung function but this was only statistically significant in Period 1. CONCLUSIONS: Children's lung function (FVC and FEV1) were lower in 2017 than in 1996. Rapid urbanization may have contributed to the decline of lung function. Obesity may be a risk factor for impaired lung function in children living in Lanzhou and possibly elsewhere.

Household environmental factors and children's respiratory health: comparison of two cross-sectional studies over 25 years in Wuhan, China.

BACKGROUND: Over the recent decades, residential lifestyle and household environment have changed substantially with rapid development of industrialization and urbanization in China. Whether the prevalence of respiratory diseases changed is still lack of evidence. The objective of this study is to assess potential changes in children's respiratory disease prevalence and associated household environmental factors in Wuhan over a 25-year time interval. METHODS: Two cross-sectional studies in the Period 1 (1993 to 1996) and Period 2 (2017 to 2018) were compared in this research. Elementary school children in period 1 (N=2,517) and in period 2 (N=3,152) were recruited in Wuhan, China. The respiratory health condition, home environmental factors, and family socioeconomic status of each subject were acquired through questionnaire survey using the same protocols in both periods. We used the Chi-square test to analyze the difference of household environmental factors (focused on three indoor air quality determinants) and children's respiratory health condition between two periods. Logistic regression models were used to assess the impacts of household environmental determinants on children's respiratory diseases and symptoms between the two studies, by adjusting a set of covariates. RESULTS: The three indoor air quality determinants have reduced substantially in prevalence from period 1 to period 2: environment tobacco smoke (ETS) from 86.6% to 45.9%, household coal use from 47.6% to 4.9%, and kitchen smoke from 58.9% to 7.3%. The prevalence of certain respiratory symptoms in children significantly decreased, such as cough with colds (51.1% to 41.6%) and phlegm with colds (22.3% to 17.7%). The prevalence of asthma was 2.5% and 2.4% and that of bronchitis was 27.1% and 29.8% in both periods. Coal use was a risk factor for asthma in period 1 (OR =2.34, 95% CI: 1.30-4.23), while it was not significantly associated with prevalence of asthma in period 2 (OR =0.60, 95% CI: 0.08-4.51). CONCLUSIONS: Household indoor air quality determinants and respiratory health condition of children in Wuhan has been improved over the last 25 years. At present, kitchen smoke is an important factor affecting the prevalence of wheeze whatever child has a cold or not and reducing exposure to ETS could be beneficial to protect children to be less likely to develop bronchitis.