Associations between Individual Exposure to Fine Particulate Matter Elemental Constituent Mixtures and Blood Lipid Profiles: A Panel Study in Chinese People Aged 60-69 Years

Dyslipidemia may be a potential mechanism linking fine particulate matter (PM_2.5) to adverse cardiovascular outcomes. However, inconsistent associations between PM_2.5 and blood lipids have resulted from the existing research, and the joint effect of PM_2.5 elemental constituents on blood lipid profiles remains unclear. We aimed to explore the overall associations between PM_2.5 elemental constituents and blood lipid profiles and to identify the significant PM_2.5 elemental constituents in this association. Sixty-nine elderly people were recruited between September 2018 and January 2019. Each participant completed a survey questionnaire, 3 days of individual exposure monitoring, health examination, and biological sample collection at each follow-up visit. Bayesian kernel machine regression (BKMR) models were used to identify the joint effects of the 17 elemental constituents on blood lipid profiles. Total cholesterol, low-density lipoprotein cholesterol (LDL-C), and non-high-density lipoprotein cholesterol (non-HDL-C) levels were significantly increased in older adults when exposed to the mixture of PM_2.5 elemental constituents. Copper and titanium had higher posterior inclusion probabilities than other constituents, ranging from 0.76 to 0.90 (Cu) and 0.74 to 0.94 (Ti). Copper and titanium in the PM_2.5 elemental constituent mixture played an essential role in changes to blood lipid levels. This study highlights the importance of identifying critical hazardous PM_2.5 constituents that may cause adverse cardiovascular outcomes in the future.

Development of a method to determine workers' personal exposure levels to glyphosate

OBJECTIVES

We aimed to develop a method to determine workers' personal exposure levels to N-(phosphonomethyl)glycine (glyphosate) for their risk assessments.

METHODS

The proposed method was assessed as follows: recovery, stability of samples on storage, method limit of quantification, and reproducibility. Glyphosate in air was sampled using an air-sampling cassette containing a glass fiber filter. Ultrapure water was used to extract glyphosate from sampler filters. After derivation with 9-fluorenylmethyloxycarbonyl chloride, samples were analyzed by high-performance liquid chromatography using a fluorescence detector.

RESULTS

Spiked samples indicated an overall recovery of 101%. After 7 days of storage at 4°C, recoveries were approximately 100%. The method limit of quantification was 0.060 μg/sample. Relative standard deviations representing overall reproducibility, defined as precision, were 1.4%-1.8%.

CONCLUSIONS

The method developed in this study allows 4-h personal exposure monitoring of glyphosate at 0.250-500 μg/m3 . Thus, this method can be used to estimate worker exposure to glyphosate.

Exploring the external exposome using wearable passive samplers - The China BAPE study

Environmental exposures are one of the greatest threats to human health, yet we lack tools to answer simple questions about our exposures: what are our personal exposure profiles and how do they change overtime (external exposome), how toxic are these chemicals, and what are the sources of these exposures? To capture variation in personal exposures to airborne chemicals in the gas and particulate phases and identify exposures which pose the greatest health risk, wearable exposure monitors can be deployed. In this study, we deployed passive air sampler wristbands with 84 healthy participants (aged 60-69 years) as part of the Biomarkers for Air Pollutants Exposure (China BAPE) study. Participants wore the wristband samplers for 3 days each month for five consecutive months. Passive samplers were analyzed using a novel gas chromatography high resolution mass spectrometry data-processing workflow to overcome the bottleneck of processing large datasets and improve confidence in the resulting identified features. The toxicity of chemicals observed frequently in personal exposures were predicted to identify exposures of potential concern via inhalation route or other routes of airborne contaminant exposure. Three exposures were highlighted based on elevated toxicity: dichlorvos from insecticides (mosquito/malaria control), naphthalene partly from mothballs, and 183 polyaromatic hydrocarbons from multiple sources. Other exposures explored in this study are linked to diet and personal care products, cigarette smoke, sunscreen, and antimicrobial soaps. We highlight the potential for this workflow employing wearable passive samplers for prioritizing chemicals of concern at both the community and individual level, and characterizing sources of exposures for follow up interventions.

[Study on the Establishment of a Specific Similar Exposure Group (SEG) in Personal Exposure Monitoring: A Case Report of Indium Tin Oxide Target Surface Grinding Process]

Surface grinding workers of Indium Tin Oxide target material are exposed to an indium compound with high toxicity. We divided individual exposure workers into similar exposure groups (SEG) and examined the effectiveness of the classification of SEG. Sampling was carried out twice a day for a total of 10 times, in 9 of which a work environment measurement in unit work area was performed at the same time. The classification examined two methods. One method was to set all the workers in the work place as one group (SEG1), and the other was to classify them depending on whether the workers handled the target material contained indium or not (SEG2). The group handled indium-contained material was SEG2(+) n=9, and the other was SEG2(-) n=9. Only the arithmetic mean value (AM) of four groups 2.8-27.4 µg/m³ in the SEG2(+) was lower than the measurement B value of the work environment measurement, but the AM of all the groups in SEG2(+) 2.8-276.8 µg/m³ was higher than the geometric mean value of measurement A 0.4-12.3 µg/m³. The concentration range of 100 μg/m³ or more of SEG2(+) AM was 20% of the total. This range was not recognized in the other items, and the variation of SEG2(+) was small. Even though the evaluation of SEG1 is control class 2, if revaluated on SEG2(+), 50% of the SEG2(+) were evaluated as control class 3. It is possible to efficiently manage chemical substances by establishing specific SEG properly stratified.

Advanced Smartphone-Based Sensing with Open-Source Task Automation

Smartphone-based sensing is becoming a convenient way to collect data in science, especially in environmental research. Recent studies that use smartphone sensing methods focus predominantly on single sensors that provide quantitative measurements. However, interdisciplinary projects call for study designs that connect both, quantitative and qualitative data gathered by smartphone sensors. Therefore, we present a novel open-source task automation solution and its evaluation in a personal exposure study with cyclists. We designed an automation script that advances the sensing process with regard to data collection, management and storage of acoustic noise, geolocation, light level, timestamp, and qualitative user perception. The benefits of this approach are highlighted based on data visualization and user handling evaluation. Even though the automation script is limited by the technical features of the smartphone and the quality of the sensor data, we conclude that task automation is a reliable and smart solution to integrate passive and active smartphone sensing methods that involve data processing and transfer. Such an application is a smart tool gathering data in population studies.

Respirable silica and noise exposures among stone processing workers in northern Thailand

Silica and noise are highly prevalent occupational exposures in the stone processing industry. Monitoring for silica and noise are expensive tasks that may be especially difficult to perform in low-resource settings, but exposure awareness is vital for protecting worker health. This study evaluated personal noise and silica measurements at a stone processing facility in northern Thailand to investigate the differing exposure potentials and risk for overexposure among the varying job categories. Our research team performed repeated personal noise and respirable silica measurements on 46 workers, over three separate workshifts for each of 46 workers. While 36.2% of noise measurements exceeded the recommended exposure limit of 85 dBA, only three silica measurements (2.4%) were above the threshold limit value (TLV) of 25 µg/m³. Self-reported personal protective equipment use was low, with only 27.5% of participants wearing hearing protection in noisy environments during their monitored shift and 29.7% of workers wearing respiratory protection during dusty portions of their shift. We identified a significant positive correlation between measured noise and silica levels (r = 0.54, p < 0.01), with stone loaders having the highest average noise (mean = 89 dBA, standard deviation = 4.9 dBA) and silica (geometric mean = 6.4 µg/m³, geometric standard deviation = 1.8) exposure levels. In a multivariate model, the stone loader job category was a significant predictor of exposure to detectable levels of respirable silica (p < 0.01). These results provide useful guidance regarding the need for noise and silica exposure interventions in order to reduce incidences of workplace disease in the stone processing industry.

Occupational exposure levels of static magnetic field during routine MRI examination in 3T MR system

Occupational exposure to the high static magnetic fields (SMFs) during magnetic resonance imaging (MRI) examinations raises concerns of adverse health effects. In this study, personal exposure monitoring of the magnetic fields during routine examinations in two 3 T MRI systems was carried out. A three-axis Hall magnetometer was attached to a subject's chest during monitoring. Data acquisition started every time the subject entered the scanner room and ended when the subject exited the room. Four radiologic technologists from two different institutes participated in this study. The maximum exposed field ranged from 0 to 1250 mT and the average peak magnetic field (B) was 428 ± 231 mT (mean ± standard deviation (SD): number of samples (N) = 103). Then, the relationship between exposure levels and work duties was analyzed. The MRI examination of the head or neck showed the highest average peak B among four work categories. These results provide information of real exposure levels for 3 T MRI system operators and can also improve the current practical training advice for preventing extra occupational field exposure.

Exploration of the rapid effects of personal fine particulate matter exposure on arterial hemodynamics and vascular function during the same day

BACKGROUND

Levels of fine particulate matter [≤ 2.5 μm in aerodynamic diameter (PM(2.5))] are associated with alterations in arterial hemodynamics and vascular function. However, the characteristics of the same-day exposure-response relationships remain unclear.

OBJECTIVES

We aimed to explore the effects of personal PM(2.5) exposures within the preceding 24 hr on blood pressure (BP), heart rate (HR), brachial artery diameter (BAD), endothelial function [flow-mediated dilatation (FMD)], and nitroglycerin-mediated dilatation (NMD).

METHODS

Fifty-one nonsmoking subjects had up to 5 consecutive days of 24-hr personal PM(2.5) monitoring and daily cardiovascular (CV) measurements during summer and/or winter periods. The associations between integrated hour-long total personal PM(2.5) exposure (TPE) levels (continuous nephelometry among compliant subjects with low secondhand tobacco smoke exposures; n = 30) with the CV outcomes were assessed over a 24-hr period by linear mixed models.

RESULTS

We observed the strongest associations (and smallest estimation errors) between HR and TPE recorded 1-10 hr before CV measurements. The associations were not pronounced for the other time lags (11-24 hr). The associations between TPE and FMD or BAD did not show as clear a temporal pattern. However, we found some suggestion of a negative association with FMD and a positive association with BAD related to TPE just before measurement (0-2 hr).

CONCLUSIONS

Brief elevations in ambient TPE levels encountered during routine daily activity were associated with small increases in HR and trends toward conduit arterial vasodilatation and endothelial dysfunction within a few hours of exposure. These responses could reflect acute PM(2.5)-induced autonomic imbalance and may factor in the associated rapid increase in CV risk among susceptible individuals.