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.

Exposure to blue space surroundings and depressive symptoms in young Chinese adults: The mediating role of sleep.

OBJECTIVE: Existing evidence suggests that the natural environment can influence mental health. However, limited research has focused on the relationship between blue space and depressive symptoms in young adults. To investigate the association between blue space surroundings and depressive symptoms in young adults in China and explore the underlying mechanisms. METHODS: The study was conducted between September and November 2019, including 2,743 young adults from China. We assessed the exposure to blue space around participants' living environments during June, July, and August 2019 using the Modified Normalized Difference Water Index (MNDWI). Blue indexes were calculated for 300 m, 1000 m, and 3000 m circular buffer zones near residential environments. Logistic regression models were employed to explore the associations between blue space exposures (quartiles) and depressive symptoms, exploring potential mechanisms through structural equation modeling (SEM), while accounting for potential confounders. Stratification analysis was used to identify sensitive populations. RESULTS: Depressive symptoms were found in 148 (5.3%) of the 2,743 young adults in the study. We observed a negative correlation between depressive symptoms and average MNDWIs at participants' addresses (OR: 0.84; 95%CI: 0.72-0.98), within 300m (OR: 0.81; 95%CI: 0.70-0.95), 1000m (OR: 0.80; 95%CI: 0.69-0.93), and 3000m (OR:0.77; 95%CI: 0.66-0.89) buffer zones. Within the 1000m buffer zone, sleep was found to mediate 21% of the relationship between the presence of blue space and depressive symptoms. The stratified analysis revealed a stronger association between low MNDWI levels within the 1000m buffer zone and depressive symptoms in females (P < 0.05). Additionally, average MNDWI levels within the 3000m buffer zone were associated with depressive symptoms in both females and males. CONCLUSIONS: Blue space could improve depressive symptoms, particularly in females, with sleep playing a mediating role. Incorporating blue spaces into environmental planning is important for improving mental health.

Cohort profile: China undergraduate cohort for environmental health study.

The China Undergraduate Cohort (CUC) is an ambispective cohort study with its major purpose to better understand the effects of lifetime environmental exposures on health outcomes. We recruited 5322 college students with an average age of 18.3 ± 0.7 years in China from August 23, 2019 to October 28, 2019. Follow-up surveys were conducted annually. The dataset comprises individual demographic data (e.g. age, sex, height, weight, birth date, race, home address, annual family income, contact information), health-related behavior data (smoking status, smoking cessation, passive smoking exposure, drinking habit, physical activity, dietary status), lifestyle data (physical exercise, dietary habit, length of time spent outdoors), disease history (respiratory disease history, cardiovascular disease history, urinary system disease history, etc.), mental health status data (sleep quality, self-reported stress, anxiety and depression symptoms), lung function and blood samples data. Preliminary results from our cohort have found the association between air pollution, summer heat and mercury exposure and lung function among young adults in China.

Whole blood cadmium levels and depressive symptoms in Chinese young adults: A prospective cohort study combing metabolomics.

OBJECTIVES: To investigate the association between Cd exposure and depressive symptoms in Chinese young adults. And to investigate the potential metabolic changes associated with high blood Cd concentrations. METHODS: We conducted a cohort study in 2019 and 2021. Blood Cd and depressive symptoms were collected during baseline and follow-up. The nine-item Patient Health Questionnaire (PHQ-9) scores were used to assess depressive symptoms. We used the generalized linear mixed model to estimate the association between blood Cd levels and depressive symptoms. A metabolomic and lipidomic analysis based on liquid chromatography-mass spectrometry was conducted on a total of 679 blood samples. The metabolomic data were analyzed using variance analysis and linear mixed effects models. RESULTS: Blood Cd concentrations were significantly associated with increased severity of depression symptoms [odds ratio (OR) 2.07, 95% confidence interval (CI) 1.04-4.11]. Metabolomics analysis found 93 metabolites with significant statistical differences between the lowest blood Cd level group and the highest Cd level group. Among the 93 differential metabolites, 17 were enriched in 7 differential metabolic pathways. CONCLUSIONS: Blood Cd was associated with increased severity of depression symptoms in Chinese young adults. Cd exposure may affect depressive symptoms by inducing oxidative stress, inflammation, and disrupting amino acid metabolism.

Blood multiple heavy metals exposure and lung function in young adults: A prospective Cohort study in China.

The content of single heavy metal in blood is associated with lung function decline, but there is little evidence on the joint effect of multiple heavy metals on lung function. To explore whether heavy metal mixture exposure is associated with lung function reduction among young adults. The study based on a cohort of 518 students recruited from a college in Shandong, China. We measured their lung function and blood heavy metal concentrations. The BKMR model was used to analyse the association between blood heavy metals mixture levels and lung function, and to identify the critical single heavy metal which contributes most to joint effects. As the sensitivity analysis, we used quantile g-computation model and GLM to explore the joint effect and independent effects of heavy metals. Our findings revealed a significant reduction of FVC and FEV1 levels after exposure to heavy metals mixture. An IQR increase in Cu was associated with a 0.079 L and 0.083 L decrease in FEV1 and FVC, respectively. And an IQR increase in Fe was associated with 0.036 L higher FEV1 and 0.033 L higher FVC. For adults, reducing blood heavy metals concentration might be an effective intervention to protect lung function.

Association between mercury exposure and lung function in young adults: A prospective cohort study in Shandong, China.

BACKGROUND: Mercury has been associated with many adverse health outcomes. However, limited studies have explored the association between blood mercury concentrations and lung function. OBJECTIVE: To examine the association between blood mercury concentrations and lung function among young adults. METHODS: We conducted a prospective cohort study among 1800 college students based on the Chinese Undergraduates Cohort in Shandong, China during August 2019 and September 2020. Lung function indicators including forced vital capacity (FVC, ml), forced expiratory volume in 1 s (FEV1, ml) and peak expiratory flow (PEF, ml) were collected with a spirometers (Chestgraph Jr. HI-101, Chest M.I., Tokyo, Japan). The blood mercury concentration was measured using inductively coupled plasma mass spectrometry. We divided participants into low (≤25 percentiles), intermediate (25-75 percentiles), and high (≥75 percentile) subgroups according to blood mercury concentrations. The multiple linear regression model was used to examine the associations between blood mercury concentrations and lung function changes. Stratification analyses by sex and fish consumption frequency were also conducted. RESULTS: The results showed that each 2-fold increase in blood mercury concentrations was significantly associated with -70.75 ml [95 % confidence interval (CI): -122.35, -19.15] change in FVC, -72.68 ml (95%CI: -120.36, -25.00) in FEV1, and -158.06 ml (95%CI: -283.77, -32.35) in PEF. The effect was more pronounced among participants with high blood mercury and male participants. Participants who consumed fish more than once a week more likely to be affected by mercury. CONCLUSION: Our study indicated that blood mercury was significantly associated with decreased lung function in young adults. It is necessary to implement corresponding measures to reduce the effect of mercury on the respiratory system, especially for men and people who consumed fish more than once a week.

Long-term improvement of air quality associated with lung function benefits in Chinese young adults: A quasi-experiment cohort study.

INTRODUCTION: Long-term exposure to air pollution is associated with lung function impairment. However, whether long-term improvements in air quality could improve lung function is unclear. OBJECTIVES: To examine whether the reduction of long-term air pollution was associated with lung function improvement among Chinese young adults. METHODS: We conducted a prospective quasi-experiment cohort study with 1731 college students in Shandong, China from September 2019 to September 2020, covering COVID-19 lockdown period. Data on air pollution concentrations were obtained from China Environmental Monitoring Station. Lung function indicators included forced vital capacity (FVC), forced expiratory volume in 1st second (FEV1) and forced expiratory flow at 50 % of FVC (FEF50%). We used linear mixed-effects model to examine the associations between the change of air pollutants concentrations and the change of lung function, and additional adjustments for indoor air pollution (IAP) source. We also conducted stratified analysis by sex. RESULTS: Compared with 2019, the mean FVC, FEV1 and FEF50% were elevated by 414.4 ml, 321.5 ml, and 28.4 ml/s respectively in 2020. Every 5 µg/m3 decrease in annual average PM2.5 concentrations was associated with 36.0 ml [95 % confidence interval (CI):6.0, 66.0 ml], 46.1 ml (95 % CI:16.7, 75.5 ml), and 124.2 ml/s (95 % CI:69.5, 178.9 ml/s) increment in the FVC, FEV1, and FEF50%, respectively. Similar associations were found for PM10. The estimated impact was almost unchanged after adjusting for IAP source. There was no significant effect difference between males and females. CONCLUSION: Long-term improvement of air quality can improve lung function among young adults. Stricter policies on improving air quality are needed to protect human health.

Efficacy of phytic acid as an inhibitor of enzymatic and non-enzymatic browning in apple juice.

Browning decreases the commercial value of apple juice, and therefore colour preservation during processing and storage is the main objective of manufacturers. In this study, the efficacy of phytic acid as a browning inhibitor for use on apple juice was investigated. Browning of apple juice treated with phytic acid was monitored during processing and storage. 0.1 mM Phytic acid inhibited the polyphenol oxidase (PPO) from the apple juice by 99.2%. Consequently, the apple juice treated with phytic acid had significantly lower browning formation during processing and after 6 months of storage at room temperature compared with the control (p<0.05). Results indicate that this is a promising way to inhibit browning in apple juice.