Fine particulate matter constituents and heart rate variability: A panel study in Shanghai, China

Short-term exposure to ultrafine and fine particulate matter with multipollutant modelling on heart rate variability among seniors and children from the CorPuScula (coronary, pulmonary, sanguis) longitudinal study in Germany

Background

Short-term exposure particulate matter with a diameter of 10 µm or less (PM10) and fine particulate matter (PM2.5) has been associated with heart rate variability (HRV), but exposure to ultrafine particles (UFP) has been less well examined. We investigated the associations between the HRV outcomes and short-term exposure to UFP, PM10 and PM2.5 among school-aged children and seniors.

Methods

CorPuScula (Coronary, Pulmonary and Sanguis) is a longitudinal, repeated-measure panel study conducted in 2000-2002 in Munich, Germany including 52 seniors (58-94 years old) with 899 observations and 50 children (6-10 years old) with 925 observations. A 10-min resting electrocardiogram was performed to assess resting HRV outcomes [Standard Deviation of Normal to Normal Intervals (SDNN), Root Mean Square of Successive Differences between Normal Heartbeats (RMSSD), Low Frequency power (LF), High Frequency power (HF), ration between low and high frequency (LF/HF)]. UFP and PM exposures were measured near the care home and school yard for seniors and children, respectively. Mean exposures during the day of examination (9-21 h) as well as 3-h, 12-h, 24-h, one-day, and two-day lags were assessed. Linear mixed-effect models were used to investigate the associations between short-term air pollution and HRV outcomes separately in children and seniors. The models were adjusted for sex, age, weather conditions (temperature, precipitation, and water vapor pressure), BMI, lifestyle and medical information. Two and multipollutant models adjusted for NO2 and O3 were performed.

Results

Among seniors, we observed increases in SDNN, LF, HF and LF/HF ratio after short-term exposure to UFP (hourly and daily lags) in contrast to decreases in SDNN and RMSSD after exposure to PM10. Associations were generally robust to two- and multipollutant adjustment. Among children, we observed increases of the LF/HF ratio after short-term exposures to UFP at lags 12 and 24 h. In contrast, we observed decreases of the ratio after exposure to PM2.5 and PM10. Results were largely unchanged for multipollutant modelling, however we found a more pronounced increase in SDNN and LF/HF (UFP lag 12 and 24 h) after adjusting for NO2.

Conclusions

Overall, among seniors, we observed associations of UFP and PM10 exposure with sympathetic responses of the ANS, which play an important role in sudden heart attacks or arrhythmia. Among children we found more inconsistent associations between UFP and a delayed increase in HRV. Adjusting for co-pollutants including NO2 and O3 yielded robust results.

Short-term effects of fine particulate matter constituents on myocardial infarction death

Existing evidence suggested that short-term exposure to fine particulate matter (PM_2.5) may increase the risk of death from myocardial infarction (MI), while PM_2.5 constituents responsible for this association has not been determined. We collected 12,927 MI deaths from 32 counties in southern China during 2011-2013. County-level exposures of ambient PM_2.5 and its 5 constituents (i.e., elemental carbon (EC), organic carbon (OC), sulfate (SO₄^2-), ammonium (NH₄⁺), and nitrate (NO₃^-)) were aggregated from gridded datasets predicted by Community Multiscale Air Quality Modeling System. We employed a space-time-stratified case-crossover design and conditional logistic regression models to quantify the association of MI mortality with short-term exposure to PM_2.5 and its constituents across various lag days. Over the study period, the daily mean PM_2.5 mass concentration was 77.8 (standard deviation (SD) = 72.7) µg/m³. We estimated an odds ratio of 1.038 (95% confidence interval (CI): 1.003-1.074), 1.038 (1.013-1.063) and 1.057 (1.023-1.097) for MI mortality associated with per interquartile range (IQR) increase in the 3-day moving-average exposure to PM_2.5 (IQR = 76.3 µg/m³), EC (4.1 µg/m³) and OC (9.1 µg/m³), respectively. We did not identify significant association between MI death and exposure to water-soluble ions (SO₄^2-, NH₄⁺ and NO₃^-). Likelihood ratio tests supported no evident violations of linear assumptions for constituents-MI associations. Subgroup analyses showed stronger associations between MI death and EC/OC exposure in the elderly, males and cold months. Short-term exposure to PM_2.5 constituents, particularly those carbonaceous aerosols, was associated with increased risks of MI mortality.

LASSO and attention-TCN: a concurrent method for indoor particulate matter prediction

Long time exposure to indoor air pollution environments can increase the risk of cardiovascular and respiratory system damage. Most previous studies focus on outdoor air quality, while few studies on indoor air quality. Current neural network-based methods for indoor air quality prediction ignore the optimization of input variables, process input features serially, and still suffer from loss of information during model training, which may lead to the problems of memory-intensive, time-consuming and low-precision. We present a novel concurrent indoor PM prediction model based on the fusion model of Least Absolute Shrinkage and Selection Operator (LASSO) and an Attention Temporal Convolutional Network (ATCN), together called LATCN. First, a LASSO regression algorithm is used to select features from PM1, PM2.5, PM10 and PM (>10) datasets and environmental factors to optimize the inputs for indoor PM prediction model. Then an Attention Mechanism (AM) is applied to reduce the redundant temporal information to extract key features in inputs. Finally, a TCN is used to forecast indoor particulate concentration in parallel with inputting the extracted features, and it reduces information loss by residual connections. The results show that the main environmental factors affecting indoor PM concentration are the indoor heat index, indoor wind chill, wet bulb temperature and relative humidity. Comparing with Long Short-Term Memory (LSTM) and Gated Recurrent Unit (GRU) approaches, LATCN systematically reduced the prediction error rate (19.7% ~ 28.1% for the NAE, and 16.4% ~ 21.5% for the RMSE) and improved the model running speed (30.4% ~ 81.2%) over these classical sequence prediction models. Our study can inform the active prevention of indoor air pollution, and provides a theoretical basis for indoor environmental standards, while laying the foundations for developing novel air pollution prevention equipment in the future.

Changes in heart rate variability of healthy subjects shortly exposed to printing shop particles and the effect of air purifier intervention

Particulate matter (PM) released by printers may cause airway inflammation and cardiac electrophysiological changes. We conducted a two-stage crossover study to examine the association between short-term exposure to printing shop particles (PSPs) and the heart rate variability (HRV) among healthy volunteers, as well as to evaluate the effect of air purifier intervention. The on-site assessments of PSPs and individual HRV parameters of the volunteers were used to analyze the influence of size-fractionated PSPs and air purifier intervention on HRV at different lag times after PSPs exposure (0 min, 5 min, 15 min, and 30 min) by using the linear mixed-effects models. We observed that changes in 6 HRV parameters were associated with particle mass concentration (PMC) of PSPs, and changes in 8 HRV parameters were associated with particle number concentration (PNC) of PSPs. The sensitive HRV parameters were the square root of the mean of the sum of the squares of differences between adjacent NN intervals (rMSSD), NN50 count divided by the total number of all NN intervals (pNN50), normalized high frequency power (nHF), very high frequency power (VHF), normalized low frequency power (nLF), and the ratio of low frequency power to high frequency power (LF/HF). Most HRV parameters exhibited the strongest effect associated with PMC and PNC at a lag time of 30 min. The air purifier intervention markedly reduced the PNC and PMC of size-fractionated PSPs, enhanced 5 HRV parameters, and decreased the nLF and LF/HF. Our study suggests that short-term exposure to PSPs can affect HRV parameters, reflecting changes in cardiac autonomic nervous activity, and the use of an air purifier can reduce the concentration of PSPs and improve the autonomic nervous system activity of the exposed individuals.

Subclinical cardiovascular outcomes of acute exposure to fine particulate matter and its constituents: A glutathione S-transferase polymorphism-based longitudinal study

To explore the acute subclinical cardiovascular effects of fine particulate matter (PM_2.5) and its constituents, a longitudinal study with 61 healthy young volunteers was conducted in Xinxiang, China. Linear mixed-effect models were used to analyze the association of PM_2.5 and its constituents with cardiovascular outcomes, respectively, including blood pressure (BP), heart rate (HR), serum levels of high-sensitivity C-reactive protein (hs-CRP), 8-hydroxy-2'-deoxyguanosine (8-OHdG), tissue-type plasminogen activator (t-PA), and platelet-monocyte aggregation (PMA). Additionally, the modifying effects of glutathione S-transferase mu 1 (GSTM1) and glutathione S-transferase theta 1 (GSTT1) polymorphisms were examined. A 10 μg/m³ increase in PM_2.5 was associated with -1.04 (95 % CI: -1.86 to -0.22) mmHg and -0.90 (95 % CI: -1.69 to -0.11) mmHg decreases in diastolic BP (DBP) and mean arterial BP (MABP) along with 1.83 % (95 % CI: 0.59-3.08 %), 5.93 % (95 % CI: 0.70-11.16 %) increases in 8-OHdG and hs-CRP, respectively. Ni content was positively associated with the 8-OHdG levels whereas several other metals presented negative association with 8-OHdG and HR. Intriguingly, GSTT1+/GSTTM1+ subjects showed higher susceptibility to PM_2.5-induced alterations of DBP and PMA, and GSTT1-/GSTM1+ subjects showed higher alteration on t-PA. Taken together, our findings indicated that short-term PM_2.5 exposure induced oxidative stress, systemic inflammation, autonomic alterations, and fibrinolysis in healthy young subjects. Among multiple examined metal components Ni appeared to positively associated with systematic oxidative stress. In addition, GST-sufficient subjects might be more prone to PM_2.5-induced autonomic alterations.

A Case-Crossover Analysis of the Association between Exposure to Total PM2.5 and Its Chemical Components and Emergency Ambulance Dispatches in Tokyo

A limited number of studies have investigated the association between short-term exposure to PM_2.5 components and morbidity. The present case-crossover study explored the association between exposure to total PM_2.5 and its components and emergency ambulance dispatches, which is one of the indicators of morbidity, in the 23 Tokyo wards. Between 2016 and 2018 (mean mass concentrations of total PM_2.5 13.5 μg/m³), we obtained data, from the Tokyo Fire Department, on the daily cases of ambulance dispatches. Fine particles were collected at a fixed monitoring site and were analyzed to estimate the daily mean concentrations of carbons and ions. We analyzed 1038301 cases of health-based all-cause ambulance dispatches by using a conditional logistic regression model. The average concentrations of total PM_2.5 over one and the previous day were positively associated with the number of ambulance dispatches. In terms of PM_2.5 components, the percentage increase per interquartile range (IQR) increase was 0.8% for elemental carbon (IQR = 0.8 μg/m³; 95% CI = 0.3-1.3%), 0.9% for sulfate (2.1 μg/m³; 0.5-1.4%), and 1.1% for ammonium (1.3 μg/m³; 0.4-1.8%) in the PM_2.5-adjusted models. This is the first study to find an association between some specific components in PM_2.5 and ambulance dispatches.

Longitudinal relationships between polycyclic aromatic hydrocarbons exposure and heart rate variability: Exploring the role of transforming growth factor-β in a general Chinese population

We aim to investigate the long-term adverse effects of polycyclic aromatic hydrocarbons (PAHs) exposure on heart rate variability (HRV) reduction, and to assess the potential role of transforming growth factor-β1 (TGF-β1) in such relationship. We enrolled 2985 adult residents with 4100 observations who participated at baseline and 6-years follow-up from Wuhan-Zhuhai cohort. Ten detectable urinary PAHs metabolites and two HRV indices were repeatedly measured at baseline and follow-up; and plasma TGF-β1 levels were also determined for all subjects. We observed that both total urinary low molecular weight PAHs (ΣLWM OH-PAH) and total urinary high molecular weight PAHs (ΣHWM OH-PAH) were negatively associated with HRV reductions (P < 0.05). Subjects with persistent high levels of ΣHWM OH-PAH had a significant reduction in HRV over 6 years, and the incensement of TGF-β1 could aggravate above adverse effects in a dose-response manner. All kinds of PAHs were positively associated with plasma TGF-β1 elevation, which in turn, were negatively related to HRV indices. Increased TGF-β1 significant mediated 1.34-3.62% of PAHs-associated HRV reduction. Our findings demonstrated that long-term high levels of PAHs exposure could cause HRV reductions, and TGF-β1 may play an essential role in such association.

Acute effects of fine particulate matter constituents on cardiopulmonary function in a panel of COPD patients

BACKGROUND

Exposure to fine particulate matter (PM_2.5) has been linked with adverse cardiorespiratory health conditions. However, evidence for PM_2.5 constituents is still scarce, especially among patients with chronic obstructive pulmonary disease (COPD).

OBJECTIVE

To investigate the associations of short-term exposure to different chemical constituents of PM_2.5 with measures of cardiac and lung function in COPD patients.

METHODS

We conducted a retrospective panel study among 100 COPD patients who received repeated measures of left ventricular ejection fraction (LVEF), forced expiratory volume in 1 s (FEV₁), forced vital capacity (FVC) and peak expiratory flow (PEF) in Shanghai, China from August 2014 to September 2019. Daily PM_2.5 and PM_2.5 constituents were obtained from fixed-site monitoring station. Linear mixed-effects models were used to estimate the associations of PM_2.5.

RESULTS

We found water-soluble ions of PM_2.5, mainly NO₃^-, SO₄^2-, and NH₄⁺ were robustly associated with reduced LVEF, and the reductions in LVEF associated with an IQR increase of them ranged from 1.8% to 2.0% (lag 1 d). Metal constituents such as Cu and As were associated with FEV₁, FVC and PEF. The corresponding reductions in lung function parameters for an IQR increase of them ranged from 1.4% to 2.3% (lag 0 or 1 d). These associations remained relatively robust after adjusting for total PM_2.5 mass and gaseous pollutants.

CONCLUSIONS

Our results suggest that water-soluble ions and several metal/metalloid elements might be important constituents in PM_2.5 that were associated with reduced cardiorespiratory function among COPD patients.

Particulate matter air pollution and reduced heart rate variability: How the associations vary by particle size in Shanghai, China

BACKGROUND

It remains unclear which size of particles has the strongest effects on heart rate variability (HRV).

OBJECTIVE

To explore the association between HRV parameters and daily variations of size-fractionated particle number concentrations (PNCs).

METHODS

We conducted a longitudinal repeated-measure study among 78 participants with a 24-h continuous ambulatory Holter electrocardiographic recorder in Shanghai, China, from January 2015 to June 2019. Linear mixed-effects models were employed to evaluate the changes of HRV parameters associated with PNCs of 7 size ranges from 0.01 to 10 μm after controlling for environmental and individual confounders.

RESULTS

On the concurrent day, decreased HRV parameters were associated with increased PNCs of 0.01-0.3 μm, and smaller particles showed greater effects. For an interquartile range increase in ultrafine particles (UFP, those < 0.1 μm, 2453 particles/cm³), the declines in very-low-frequency power, low-frequency power, high-frequency power, standard deviation of normal R-R intervals, root mean square of the successive differences between R-R intervals and percentage of adjacent normal R-R intervals with a difference ≥ 50 ms were 5.06% [95% confidence interval (CI): 2.09%, 7.94%], 7.65% (95%CI: 2.73%, 12.32%), 9.49% (95%CI: 4.64%, 14.09%), 5.10% (95%CI: 2.21%, 7.91%), 8.09% (95%CI: 4.39%, 11.65%) and 24.98% (95%CI: 14.70%, 34.02%), respectively. These results were robust to the adjustment of criteria air pollutants, temperature at different lags, and the status of heart medication.

CONCLUSIONS

Particles less than 0.3 μm (especially UFP) may dominate the acute effects of particulate air pollution on cardiac autonomic dysfunction.

Seasonal exposure to phthalates and inflammatory parameters: A pilot study with repeated measures

Exposure to phthalates poses potential to damage multiple organs and system in the body. However, limited data are available regarding effects of seasonal exposure levels of phthalates and indicators reflecting inflammatory response. We designed a pilot study with repeated measures. We recruited 106 eligible habitants from Wuhan city, China. They completed questionnaires, physical examinations and provided urine specimens in winter and summer seasons. We found that urinary levels of low-molecular-weight phthalate metabolites were higher in summer than in winter (all P < 0.01). In winter, an interquartile range increase (1.264 μg/L) in 3-day moving average of high-molecular-weight phthalate metabolites corresponded to a 13.634% (95% CI: -22.331, -3.941) decrease in mean platelet volume, 25.879% (95% CI: -37.424, -12.204) for lymphocyte count or 10.862% (95% CI: -18.716, -2.125) for platelet count (P < 0.05 or P < 0.01). However, in summer, an interquartile range increase (1.215 μg/L) in urinary levels of high-molecular-weight phthalate metabolites corresponded to an 8.743% (95% CI: 4.217, 13.467) increase in platelet distribution width value or a 4.597% (95% CI: 2.335, 6.780) for mean platelet volume value at 3-day lag (both P < 0.01). In conclusion, phthalate exposure exhibited the potential for the activation of platelet function, particularly in winter. Seasonal variations of phthalate exposure should be considered when assessing health risk.

Municipal Residence Level of Long-Term PM10 Exposure Associated with Obesity among Young Adults in Seoul, Korea

BACKGROUND

long-term effects of ambient pollutants used to be defined in cohort studies using biomarkers. Health effects on young adults from long-term exposure to particulate matters (PM) in residential ambiance have received less attention.

METHODS

using the data of population-representative aged 19-29 in Seoul, the relationship between obesity and PM10 levels of the living district was examined. We defined obesity as Body Mass Index (BMI) 25 kg/m2 and more. Survey logistic regression was conducted according to individual residence periods in the current municipality. Individual characteristics were adjusted overall and were age-specific; aged 19-24 and 25-29.

RESULTS

study population was 3655 (1680 (46%) men and 1933 aged 19-24 (52.9%)) individuals. Relationship between length of residence in municipalities with a greater level of PM10 from 2001-2005 and obesity was increased over the residing period; 10 years ≤ (odds ratio (OR) 1.071, 95% confidence interval (CI) 0.969-1.185), 15 years ≤ (1.120, 1.006-1.247), and 20 years ≤ (1.158, 1.034-1.297) in aged 19-29. Age-specific effects showed slight differences.

CONCLUSIONS

Although PM10 levels are currently decreasing, higher levels of PM10 exposure in the residential area during the earlier lifetime may contribute to obesity increase among young adults.