How the constituents of fine particulate matter and ozone affect the lung function of children in Tianjin, China

Oil and gas produced waters fail to meet beneficial reuse recommendations for use as dust suppressants

Produced water from conventional oil and gas wells (O&G PW) is beneficially reused as an inexpensive alternative to commercial dust suppressants which minimize inhalable particulate matter (PM10) from unpaved roads. The efficacy and environmental impacts of using O&G PW instead of commercial products have not been extensively investigated, although O&G PW has been used for dust suppression for decades and often has elevated concentrations of environmental pollutants. In this study, the effectiveness of O&G PW is compared to commercial products under variable humidity conditions by measuring total generated PM10 emissions from treated road aggregate discs. To measure environmental impacts, model roadbeds were treated with six O&G PW and commercial products then subjected to a simulated two-year, 24-h storm event. Generated runoff water was collected and characterized. In efficacy studies, O&G PW offered variable dust reduction (10-85 %) compared to rainwater controls under high humidity (50 %) conditions but performed similarly or worse than controls when humidity was low (20 %). Conversely, all but two commercial products reduced dust emissions by over 90 % regardless of humidity. In rainfall-runoff experiments, roads treated with O&G PWs and CaCl2 Brine generated runoff that was hypersaline, indicating that mobilization of soluble salts could contribute to freshwater salinization. Though most runoff concentrations were highest from roadbeds treated with CaCl2 Brine, runoff from roadbeds treated with O&G PW had the highest concentrations of combined radium (83.6 pCi/L), sodium (3560 mg/L), and suspended solids (5330 mg/L). High sodium concentrations likely dispersed clay particles, which increased road mass loss by 47.2 kg solids/km/storm event compared to rainwater controls. Roadbeds treated with CaCl2 Brine, which had low sodium concentrations, reduced solid road mass loss by 98.1 kg solids/km/storm event. Based on this study, O&G PW do not perform as well as commercial products and pose unique risks to environmental health.

Associations between long-term ozone exposure and small airways function in Chinese young adults: a longitudinal cohort study

BACKGROUND

Increasing evidence is appearing that ozone has adverse effects on health. However, the association between long-term ozone exposure and lung function is still inconclusive.

OBJECTIVES

To investigate the associations between long-term exposure to ozone and lung function in Chinese young adults.

METHODS

We conducted a prospective cohort study among 1594 college students with a mean age of 19.2 years at baseline in Shandong, China from September 2020 to September 2021. Lung function indicators were measured in September 2020 and September 2021, including forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), forced expiratory flow at the 25th, 50th, and 75th percentile of the FVC (FEF25, FEF50, and FEF75) and mean flow rate between 25% and 75% of the FVC (FEF25-75) were measured. Daily 10 km×10 km ozone concentrations come from a well-validated data-fusion approach. The time-weighted average concentrations in 12 months before the lung function test were defined as the long-term ozone exposure. The associations between long-term ozone exposure and lung function indicators in Chinese young adults were investigated using a linear mixed effects model, followed by stratified analyses regarding sex, BMI and history of respiratory diseases.

RESULTS

Each interquartile range (IQR) (8.9 µg/m3) increase in long-term ozone exposure were associated with a -204.3 (95% confidence interval (CI): -361.6, -47.0) ml/s, -146.3 (95% CI: -264.1, -28.4) ml/s, and - 132.8 (95% CI: -239.2, -26.4) ml/s change in FEF25, FEF50, and FEF25-75, respectively. Stronger adverse associations were found in female participants or those with BMI ≥ 24 kg/m2 and history of respiratory diseases.

CONCLUSION

Long-term exposure to ambient ozone is associated with impaired small airway indicators in Chinese young adults. Females, participants with BMI ≥ 24 kg/m2 and a history of respiratory disease have stronger associations.

Impact of air pollution changes and meteorology on asthma outpatient visits in a megacity in North China Plain

The effects of air pollution and meteorology on asthma is less studied in North China Plain. In the last decade, air quality in this region is markedly mitigated. This study compared the short-term effects of air pollutants on daily asthma outpatient visits (AOV) within different sex and age groups from 2014 to 2016 and 2017-2019 in Tianjin, with the application of distributed lag nonlinear model. Moreover, relative humidity (RH) and temperature as well as the synergistic impact with air pollutants were assessed. Air pollutants-associated risk with linear (different reference values were used) and non-linear assumptions were compared. In 2014-2016, PM10 and PM2.5 exhibited a larger impact on AOV, with the corresponding cumulative excess risks (ER) for every 10 μg/m3 increase at 1.04 % (95%CI:0.67-1.40 %, similarly hereafter) and 0.79 % (0.35-1.23 %), as well as increased to 43 % (26-63 %) and 20 % (10-31 %) at severe pollution. In 2017-2019, NO2 and MDA8 O3 exhibited a larger impact on AOV, with a cumulative ER for every 10 μg/m3 increase at 1.0 (0.63-1.4 %) and 0.36 % (0.15-0.57 %), with corresponding values of 7.9 % (4.8-11 %) and 5.6 % (2.3-9.0 %), at severe pollution. SO2 associated risk was only significant from 2014 to 2016. Cold effect, including extremely low temperature exposure and sharp temperature drop could generate a pronounced increase in AOV at 9.6 % (3.8-16 %) and 24 % (9.1-41 %), respectively. Moderate low temperature combined with air pollutants can enhance AOV during winter. Higher temperature in spring and autumn could trigger asthma by increasing pollen levels. Low RH resulted in AOV increase by 4.6 % (2.4-6.9), while higher RH generated AOV increase by 3.4 % (1.6-5.3). Females, children, and older adults tended to have a higher risk for air pollution, non-optimum temperature, and RH. As air pollution-associated risks on AOV tends to be weaker due to air quality improvement in recent years, the impact of extreme meteorological condition amidst climate change on asthma visits warrants further attention.

Source apportionment of heavy metals in PM2.5 samples and effects of heavy metals on hypertension among schoolchildren in Tianjin

The prevalence of hypertension in children has increased significantly in recent years in China. The aim of this study was to provide scientific support to control ambient heavy metals (HMs) pollution and prevent childhood hypertension. In this study, ambient HMs in PM2.5 were collected, and 1339 students from Tianjin were randomly selected. Positive matrix factorization (PMF) was used to identify and determine the sources of HMs pollution. The generalized linear model, Bayesian kernel machine regression (BKMR) and the quantile g-computation method were used to analyze the relationships between exposure to HMs and the risk of childhood hypertension. The results showed that HMs in PM2.5 mainly came from four sources: soil dust, coal combustion, incineration of municipal waste and the metallurgical industry. The positive relationships between As, Se and Pb exposures and childhood hypertension risk were found. Coal combustion and incineration of municipal waste were important sources of HMs in the occurrence of childhood hypertension. Based on these accomplishments, this study could provide guidelines for the government and individuals to alleviate the damaging effects of HMs in PM2.5. The government must implement policies to control prime sources of HMs pollution.

Effect of Acute PM2.5 Exposure on Lung Function in Children: A Systematic Review and Meta-Analysis

Objective

The objective of this study was to conduct a systematic review and meta-analysis to identify the adverse effects of acute PM2.5 exposure on lung function in children.

Design

Systematic review and meta-analysis. Setting, participants and measures: Eligible studies analyzing PM2.5 level and lung function in children were screened out. Effect estimates of PM2.5 measurements were quantified using random effect models. Heterogeneity was investigated with Q-test and I² statistics. We also conducted meta-regression and sensitivity analysis to explore the sources of heterogeneity, such as different countries and asthmatic status. Subgroup analyses were conducted to determine the effects of acute PM2.5 exposure on children of different asthmatic status and in different countries.

Results

A total of 11 studies with 4314 participants from Brazil, China and Japan were included finally. A 10 μg/m³ increase of PM2.5 was associated with a 1.74L/min (95% CI: -2.68, -0.90) decrease in peak expiratory flow (PEF). Since the asthmatic status and country could partly explain the heterogeneity, we conducted the subgroup analysis. Children with severe asthma were more susceptible to PM2.5 exposure (-3.11 L/min per 10 μg/m³ increase, 95% CI -4.54, -1.67) than healthy children (-1.61 L/min per 10 μg/m³ increase, 95% CI -2.34, -0.91). In the children of China, PEF decreased by 1.54 L/min (95% CI -2.33, -0.75) with a 10 μg/m³ increase in PM2.5 exposure. In the children of Japan, PEF decreased by 2.65 L/min (95% CI -3.82, -1.48) with a 10 μg/m³ increase of PM2.5 exposure. In contrast, no statistic association was found between every 10 μg/m³ increase of PM2.5 and lung function in children of Brazil (-0.38 L/min, 95% CI -0.91, 0.15).

Conclusion

Our results demonstrated that the acute PM2.5 exposure exerted adverse impacts on children's lung function, and children with severe asthma were more susceptible to the increase of PM2.5 exposure. The impacts of acute PM2.5 exposure varied across different countries.

Impact of COVID-19 lockdown on carbonaceous aerosols in a polluted city: Composition characterization, source apportionment, influence factors of secondary formation

Carbonaceous fractions throughout the normal period and lockdown period (LP) before and during COVID-19 outbreak were analyzed in a polluted city, Zhengzhou, China. During LP, fine particulate matters, elemental carbon (EC), and secondary organic aerosol (SOC) concentrations fell significantly (29%, 32% and 21%), whereas organic carbon (OC) only decreased by 4%. Furthermore, the mean OC/EC ratio increased (from 3.8 to 5.4) and the EC fractions declined dramatically, indicating a reduction in vehicle emission contribution. The fact that OC1-3, EC, and EC1 had good correlations suggested that OC1-3 emanated from primary emissions. OC4 was partly from secondary generation, and increased correlations of OC4 with OC1-3 during LP indicated a decrease in the share of SOC. SOC was more impacted by NO2 throughout the research phase, thereby the concentrations were lower during LP when NO2 levels were lower. SOC and relative humidity (RH) were found to be positively associated only when RH was below 80% and 60% during the normal period (NP) and LP, respectively. SOC, Coal combustion, gasoline vehicles, biomass burning, diesel vehicles were identified as major sources by the Positive Matrix Factorization (PMF) model. Contribution of SOC apportioned by PMF was 3.4 and 3.0 μg/m3, comparable to the calculated findings (3.8 and 3.0 μg/m3) during the two periods. During LP, contributions from gasoline vehicles dropped the most, from 47% to 37% and from 7.1 to 4.3 μg/m3, contribution of biomass burning and diesel vehicles fell by 3% (0.6 μg/m3) and 1% (0.4 μg/m3), and coal combustion concentrations remained nearly constant. The findings of this study highlight the immense importance of anthropogenic source reduction in carbonaceous component variations and SOC generation, and provide significant insight into the temporal variations and sources of carbonaceous fractions in polluted cities.

The relationship between particulate matter and lung function of children: A systematic review and meta-analysis

There have been many studies on the relationship between fine particulate matter (PM_2.5) and lung function. However, the impact of short-term or long-term PM_2.5 exposures on lung function in children is still inconsistent globally, and the reasons for the inconsistency of the research results are not clear. Therefore, we searched the PubMed, Embase and Web of Science databases up to May 2022, and a total of 653 studies about PM_2.5 exposures on children's lung function were identified. Random effects meta-analysis was used to estimate the combined effects of the 25 articles included. PM_2.5 concentrations in short-term exposure studies mainly come from individual and site monitoring. And for every 10 μg/m³ increase, forced vital capacity (FVC), forced expiratory volume in the first second (FEV₁) and peak expiratory flow (PEF) decreased by 21.39 ml (95% CI: 13.87, 28.92), 25.66 ml (95% CI: 14.85, 36.47) and 1.76 L/min (95% CI: 1.04, 2.49), respectively. The effect of PM_2.5 on lung function has a lag effect. For every 10 μg/m³ increase in the 1-day moving average PM_2.5 concentration, FEV₁, FVC and PEF decreased by 14.81 ml, 15.40 ml and 1.18 L/min, respectively. PM_2.5 concentrations in long-term exposure studies mainly obtained via ground monitoring stations. And for every 10 μg/m³ increase, FEV₁, FVC and PEF decreased by 61.00 ml (95% CI: 25.80, 96.21), 54.47 ml (95% CI: 7.29, 101.64) and 10.02 L/min (95% CI: 7.07, 12.98), respectively. The sex, body mass index (BMI), relative humidity (RH), temperature (Temp) and the average PM_2.5 exposure level modify the relationship between short-term PM_2.5 exposure and lung function. Our study provides further scientific evidence for the deleterious effects of PM_2.5 exposures on children's lung function, suggesting that exposure to PM_2.5 is detrimental to children's respiratory health. Appropriate protective measures should be taken to reduce the adverse impact of air pollution on children's health.

Health risks of PM2.5-bound polycyclic aromatic hydrocarbon (PAH) and heavy metals (PPAH&HM) during the replacement of central heating with urban natural gas in Tianjin, China

To investigate the health effects of fine particulate matter (≤ 2.5 μm in aerodynamic diameter; PM_2.5)-bound heavy metals and polycyclic aromatic hydrocarbons (PAHs) before and after the implementation of the Urban Natural Gas Heating Project (UNGHP), the lifetime cancer risks, hazard quotients (HQs) of heavy metals and PAHs were calculated. Seven kinds of heavy metals (Al, As, Cd, Cr, Mn, Ni and Se) and 12 kinds of PAHs including acenaphthylene (ANY), acenaphthene (ANA), fluoranthene (FLT), pyrene (PYR), chrysene (CHR), benz[a]anthracene (BaA), benzo[b]fluoranthene (BbF), benzo[k]fluoranthene (BkF), benzo[a]pyrene (BaP), dibenz[a,h]anthracene (DBA), benzo[ghi]perylene (BPE) and indeno[1,2,3-cd]pyrene (IPY) were analyzed and used for the health risk assessments. It was found that HQ of Mn fell from 1.09 in the coal-burning period to 0.72 in the gas-burning period in the suburban area. And lifetime cancer risks of PAHs fell from 35.7 × 10^-6 in the coal-burning period to 17.22 × 10^-6 in the gas-burning period in the urban area. It could be concluded that, during the gas-burning period, downward trends were observed for the lifetime cancer risks and HQs of most kinds of heavy metals and PAHs in all regions of Tianjin compared to those during the coal-burning period. The UNGHP was effective, and we should also take other measures to control the pollution.

Lung function among residents from the largest coal region in Brazil

Coal mining and burning activities in coal-fired power plants are among the most polluting activities in developing countries. In Brazil, the Candiota coal deposit concentrates 40% of the national mineral coal. Although, previous studies indicate several negative health outcomes to residents of this coal region, there is no information about lung function. Thus, this study aimed to evaluate lung function by spirometry among residents from the largest coal mining region of Brazil and its related factors. It was carried out a cross-sectional study with 300 male adults residing in four cities from this region. Socioeconomic, demographic, life style, and health conditions were collected through a structured questionnaire, and lung function was assessed by spirometry. Almost 18% of the residents have disorders in pulmonary function. There was significant statistical difference in the spirometry main parameters between the cities. Candiota city (host city of coal exploration activities) have the highest prevalence of obstructive ventilatory disorder. Curiously, upper economic class had significant higher risk of altered lung function (P<0.001), as well as inappropriate sewage destination (P<0.001). Residents of Candiota city had 20% higher risk of altered lung function. Regarding air quality, the PM₁₀, SO₂, and NO₂ of the region were 20.6± 3.9, 7.0± 2.2, and 6.0± 1.6, respectively. Two air quality stations exceed the limit of 20 μg/m³ to PM₁₀ proposed by Brazilian legislation and WHO, and three stations had PM₁₀ quite close to the limit. This study points out the need for urgent action to protect residents from this coal mining region.

Effects of air pollution and green spaces on impaired lung function in children: a case-control study

The occurrences of impaired lung function during childhood could substantially influence the health states of the respiratory system in adults. So, the effects of air pollution and green spaces on impaired lung function in children were investigated in this study. The lung function of each student was tested every year from 2015 to 2017 and the method of case-control study was applied. 2087 students aged from 9 to 11 years old of primary schools in Tianjin were ultimately included in this study. The method of propensity score matching (PSM) was performed to minimize the confounding bias and the conditional logistic regression model was carried out to evaluate the effects of indoor and outdoor environmental risk factors on the occurrences of impaired lung function in children. For every interquartile range (IQR) increase in the mixture of six air pollutants at the lag1, lag2, and lag3 periods, the risks of getting impaired lung function were increased by 53.4%, 34.7%, and 16.9%, respectively. The protective effect of greenness at lag2 period (odds ratios (OR)) = 0.022 (95% confidence interval (CI): 0.008-0.035)) was stronger than that at lag1and lag3 periods, respectively. Separate and combined effects of most air pollutants at different lag periods exerted hazardous effects on the lung function of students. Exposure to greenness had protective effects on the lung health of children.

Evaluating carbon content in airway macrophages as a biomarker of personal exposure to fine particulate matter and its acute respiratory effects

It remains unclear whether carbon content in airway macrophages (AM) can predict personal short-term exposure to fine particulate matter (PM_2.5) air pollution and its respiratory health effects. We aimed to evaluate the pathway from personal PM_2.5 exposure to adverse respiratory outcomes through AM carbon content. We designed a longitudinal panel study with 3 scheduled follow-ups among 113 non-smoking patients of chronic obstructive pulmonary disease in Shanghai, China, from April 2017 to January 2019. We quantified AM carbon content from induced sputum by image analysis, tested lung function and measured sputum levels of 4 pro-inflammatory cytokines and 2 anti-inflammatory cytokines. We applied the "meet in the middle" approach incorporating linear mixed-effect models to evaluate the associations from external PM_2.5 exposure to respiratory outcomes through AM carbon content. Our results indicated that personal exposure to PM_2.5 within 24 h was significantly associated with decreased forced expiratory volume in 1s and anti-inflammatory cytokines, as well as increased macrophages and pro-inflammatory cytokines. These changes were accompanied by increased areas of AM carbon and higher percentage of AM area occupied by carbon, both of which were associated with increased levels of pro-inflammatory cytokines and decreased levels of anti-inflammatory cytokines. Exposure to ambient black carbon and organic carbon in PM_2.5 within 2 days was significantly associated with increased AM carbon area and percentage of AM area occupied by carbon. Our findings reinforced the causality in respiratory health effects of PM_2.5 in which increased AM carbon content might serve as a valid exposure biomarker.

Systematic Review of Ozone Effects on Human Lung Function, 2013 through 2020

Background

Ozone effects on lung function are particularly important to understand in the context of the air pollution-health outcomes epidemiologic literature, given the complex relationships between ozone and other air pollutants with known lung function effects.

Research Question

What has been learned about the association between ozone exposures and lung function from epidemiology studies published from 2013 through 2020?

Study Design and Methods

On March 18, 2018, and September 8, 2020, PubMed was searched using the terms health AND ozone, filtering to articles in English and about humans, from 2013 or later. An additional focused review searching for ozone AND (lung function OR FEV₁OR FVC) was performed June 26, 2021. Articles were selected for this review if they reported a specific relationship between a lung function outcome and ozone exposure.

Results

Of 3,271 articles screened, 53 ultimately met criteria for inclusion. A systematic review with assessment of potential for bias was conducted, but a meta-analysis was not carried out because of differences in exposure duration and outcome quantification. Consistent evidence exists of small decreases in children’s lung function, even associated with very low levels of short-term ozone exposure. The effects on adult lung function from exposure to low-level, short-term ozone are less clear, although ozone-associated decrements may occur in the elderly. Finally, long-term ozone exposure decreases both lung function and lung function growth in children, although few new studies have examined long-term ozone and lung function in adults.

Interpretation

Much of this literature involves concentrations below the current US Environmental Protection Agency’s National Ambient Air Quality Standard of 70 parts per billion over an 8-h averaging time, suggesting that this current standard may not protect children adequately from ozone-related decrements in lung function.

Associations of fine particulate matter and its constituents with airway inflammation, lung function, and buccal mucosa microbiota in children

BACKGROUND

Previous studies have suggested acute effects of ambient fine particulate matter (PM_2.5) air pollution on respiratory health among children, but evidence for PM_2.5 constituents and respiratory health were still limited.

OBJECTIVES

To investigate associations of short-term exposure to PM_2.5 and its constituents with airway inflammation, lung function, and airway microbiota in children.

METHODS

We conducted a longitudinal panel study with 3 repeated health measurements among 62 children in Shanghai, China from November 2018 to June 2019. Respiratory health was measured by fractional exhaled nitric oxide (FeNO), saliva tumor necrosis factor-α (TNF-α), lung function (forced vital capacity and forced exhaled volume in 1 s), and microbiota diversity in buccal mucosa samples. Based on the linear mixed-effect models, we applied the single-constituent models and the constituent-PM_2.5 adjustment models to examine the associations between PM_2.5 constituents and health outcomes.

RESULT

Short-term exposure to PM_2.5 was associated with higher TNF-α, FeNO levels and reduced lung function. Among all constituents, organic carbon, elemental carbon, NO₃^- and NH₄⁺ had the consistent and strongest associations with airway inflammation biomarkers and lung function parameters, followed by metallic elements. We also found short-term PM_2.5 exposure was associated with decreased diversity in buccal mucosa bacterial community and two bacterial phyla, Fusobacteria and Proteobacteria, were identified as differential microbes with PM_2.5 exposure.

CONCLUSION

Short-term exposure to PM_2.5 may impair children's respiratory health represented by higher airway inflammation, lower lung function and altered buccal mucosa microbial colonization. Organic carbon, elemental carbon, NO₃^- and NH₄⁺ may dominate these effects.

Chemical constituents and sources of indoor PM2.5 and cardiopulmonary function in patients with chronic obstructive pulmonary disease: Estimation of individual and joint effects

BACKGROUND

The cardiopulmonary effects of chemical constituents and sources of indoor fine particulate matter (PM_2.5) remain unclear.

OBJECTIVES

To examine the individual and joint effects of constituents of indoor PM_2.5 on cardiopulmonary function of patients with chronic obstructive pulmonary disease (COPD) and the role of identified sources.

METHODS

This panel study recruited 43 stable COPD patients from November 2015 to May 2016 in Beijing, China. Daily indoor and outdoor PM_2.5 were collected for five consecutive days simultaneously. Twenty-four elements were measured and principal component analysis was used for source appointment. Pulmonary function and blood pressure (BP) were also measured at daily visit. The linear mixed-effect models were used to estimate the effect of each constituent and source. Bayesian kernel machine regression (BKMR) models were used to estimate the overall effect of all measured constituents.

RESULTS

The combustion, indoor soil/dust and road dust sources were identified as the main sources of indoor PM_2.5 and combustion sources contributed over 40% during the heating season. Most constituents were significantly associated with elevated BP of COPD patients and the joint effects of mixed exposures were also significant especially during the heating season. Most associations of chemical constituents with pulmonary function were negative but not statistically significant during the heating season, as was the joint effect. Few associations were observed during the non-heating season. Further, we observed combustion sources throughout the study period and road dust sources during the heating season were significantly associated with increased BP but not decreased pulmonary function.

CONCLUSION

The combustion and road dust sources and their related constituents of indoor PM_2.5 could cause adverse effects on cardiovascular function of COPD patients especially during the heating season, but the effect on pulmonary function still needs to be further studied.