A case study of exposure to ultrafine particles from secondhand tobacco smoke in an automobile

Characteristics of second-hand exposure to aerosols from e-cigarettes: A literature review since 2010

In recent years, the use of electronic vaping products (also named e-cigarettes) has increased due to their appealing flavors and nicotine delivery without the combustion of tobacco. Although the hazardous substances emitted by e-cigarettes are largely found to be much lower than combustible cigarettes, second-hand exposure to e-cigarette aerosols is not completely benign for bystanders. This work reviewed and synthesized findings on the second-hand exposure of aerosols from e-cigarettes and compared the results with those of the combustible cigarettes. In this review, different results were integrated based upon sampling locations such as residences, vehicles, offices, public places, and experimental exposure chambers. In addition, the factors that influence the second-hand exposure levels were identified by objectively reviewing and integrating the impacts of combustible cigarettes and e-cigarettes on the environment. It is a challenge to compare the literature data directly to assess the effect of smoking/vaping on the indoor environment. The room volume, indoor air exchange rate, puffing duration, and puffing numbers should be considered, which are important factors in determining the degree of pollution. Therefore, it is necessary to calculate the "emission rate" to normalize the concentration of pollutants emitted under various experimental conditions and make the results comparable. This review aims to increase the awareness regarding the harmful effects of the second-hand exposure to aerosols coming from the use of cigarettes and e-cigarettes, identify knowledge gaps, and provide a scientific basis for future policy interventions with regard to the regulation of smoking and vaping.

TAPaC-tobacco-associated particulate matter emissions inside a car cabin: establishment of a new measuring platform

Background

Particulate matter (PM) emission caused by tobacco combustion leads to severe health burdens worldwide. Second-hand smoke exposure is extraordinarily high in enclosed spaces (e.g., indoor rooms, car cabins) and poses a particular threat to the health of vulnerable individuals (e.g., children, elderly, etc.). This study aimed to establish a new measuring platform and investigate PM emissions under four different ventilation conditions inside a car cabin without exposing any person to harmful tobacco smoke.

Methods

PM concentrations were measured during the smoking of 3R4F reference cigarettes in a Mitsubishi Space Runner (interior volume 3.709 m³). The cigarettes were smoked with a machine, eliminating exposure of the researchers. Cigarettes were extinguished 4.5 min after ignition, and PM measurements continued until 10 min after ignition.

Results

High mean PM concentrations were measured for cigarettes without ventilation after 4.5 min (PM₁₀: 1150 µg/m³, PM_2.5: 1132 µg/m³, PM₁: 861.6 µg/m³) and after 10 min (PM₁₀: 1608 µg/m³, PM_2.5: 1583 µg/m³, PM₁: 1133 µg/m³). 3R4F smoked under conditions with turned on ventilation resulted in reduction of PM compared to those smoked without ventilation after 4.5 min (PM₁₀:-47.5 to -58.4%, PM_2.5:-47.2 to -58%, PM₁:-39.6 to -50.2%) and after 10 min (PM₁₀:-70.8 to -74.4%, PM_2.5:-70.6 to -74.3%, PM₁:-64.0 to -68.0%). Cigarettes smoked without ventilation generated high PM peaks at 4.5 min (PM₁₀: 2207 µg/m³, PM_2.5: 2166 µg/m³, PM₁: 1421 µg/m³) and at 10 min (PM₁₀: 1989 µg/m³, PM_2.5: 1959 µg/m³, PM₁: 1375 µg/m³). PM peaks of cigarettes smoked under different ventilation modes varied at 4.5 min (PM₁₀: 630-845 µg/m³, PM_2.5: 625-836 µg/m³, PM₁: 543 - 693 µg/m³) and 10 min (PM₁₀: 124 - 130 µg/m³, PM_2.5: 124 - 129 µg/m³, PM₁: 118 - 124 µg/m³).

Conclusion

The new measuring platform provides a safer way for researchers to investigate PM emissions of cigarettes. These data are comparable to published research and show that smoking in a parked vehicle with the windows closed generates harmful PM emissions even when the vehicle ventilation is in operation. Future studies should be carried out using the new measuring platform investigating PM exposure and PM distribution of in-vehicle smoking under a wide range of conditions.

Improving the electrospinning process of fabricating nanofibrous membranes to filter PM2.5

To mitigate PM2.5 emissions is becoming a pressing concern, because these particles pose a threat to public health. Evidence shows that bead-free nanofiber with diameter of <100 nm is more likely to capture the PM2.5, however, currently it is impossible to fabricate bead-free nanofiber with such diameter without introduction of other substances. To fabricate bead-free polyacrylonitrile (PAN) nanofibers with diameter of <100 nm, we improved the electrospinning process of membrane fabrication via design of experiment (DOE), and we then used these nanofibers to filter PM2.5 emissions from burning cigarettes and fused deposition modeling (FDM) three-dimensional (3D) printing. The DOE was based on a L₂₇ (3¹³) orthodoxy array, which consists of six controllable factors, that is, the concentration of solution, the spinning voltage, the rotating speed, the tip-to-collector distance, the flow rate of the syringe pump, and the electrospinning temperature, each of them has three levels. The results showed that the nanofibers of the least diameter (i.e., 77 nm) can be fabricated under the following condition: 8 wt% PAN solution, 12 kV voltage, 5000 r/min, 12 cm tip-to-collector distance, 0.6 ml/h flow rate, and 50 °C electrospinning temperature. Range analysis and analysis of variance (ANOVA) showed that the concentration of PAN solution has the most significant effect on the diameter, and their values are positively correlated. An examination in a two-chamber filtering device showed the PAN membrane with the least fiber diameter has a PM2.5 filtration efficiency of 99.26%. A filtration test on standard FDM 3D printing process showed the membrane has a PM2.5 removal efficiency of 81.16%. This work could mitigate PM2.5 emissions from cigarette tobacco and FDM 3D printing, and it would be used to other scenarios, such as industrial and traffic emissions.

Passive exposure to pollutants from conventional cigarettes and new electronic smoking devices (IQOS, e-cigarette) in passenger cars

Smoking in car interiors is of particular concern because concentrations of potentially harmful substances can be expected to be high in such small spaces. To assess the potential exposure for occupants, especially children, we performed a comprehensive evaluation of the pollution in 7 passenger cars while tobacco cigarettes and new electronic smoking products (IQOS, e-cigarette) were being smoked. We collected data on the indoor climate and indoor air pollution with fine and ultrafine particles and volatile organic compounds while the cars were being driven. Smoking of an IQOS had almost no effect on the mean number concentration (NC) of fine particles (>300 nm) or on the PM_2.5 concentration in the interior. In contrast, the NC of particles with a diameter of 25-300 nm markedly increased in all vehicles (1.6-12.3 × 10⁴/cm³). When an e-cigarette was vaped in the interior, 5 of the 7 tested cars showed a strong increase in the PM_2.5 concentration to 75-490 μg/m³. The highest PM_2.5 levels (64-1988 μg/m³) were measured while tobacco cigarettes were being smoked. With the e-cigarette, the concentration of propylene glycol increased in 5 car interiors to 50-762 μg/m³, whereby the German indoor health precaution guide value for propylene glycol was exceeded in 3 vehicles and the health hazard guide value in one. In 4 vehicles, the nicotine concentration also increased to 4-10 μg/m³ while the e-cigarette was being used. The nicotine concentrations associated with the IQOS and e-cigarette were comparable, whereas the highest nicotine levels (8-140 μg/m³) were reached with tobacco cigarettes. Cigarette use also led to pollution of the room air with formaldehyde (18.5-56.5 μg/m³), acetaldehyde (26.5-141.5 μg/m³), and acetone (27.8-75.8 μg/m³). Tobacco cigarettes, e-cigarettes, and the IQOS are all avoidable sources of indoor pollutants. To protect the health of other non-smoking passengers, especially that of sensitive individuals such as children and pregnant women, these products should not be used in cars.

A systematic review of secondhand smoke exposure in a car: Attributable changes in atmospheric and biological markers

Exposure to secondhand smoke (SHS) has been linked to disease, disability, and premature death. While several countries have enacted smoke-free legislations, exposure to SHS may still occur in unregulated private environments, such as in the family car. We performed a systematic review of peer-reviewed literature in PubMed and Web of Science up to May 2013. Articles were selected if they provided a quantitative measure of SHS exposure (biological or atmospheric markers); the study was conducted inside a car; and the assessed exposure was attributable to cigarette combustion. From 202 articles identified, 12 met the inclusion criteria. Among all studies that assessed smoking in cars with at least one window partially open, the particulate matter 2.5 μm or less in diameter (PM2.5) concentrations ranged from 47 μg/m(3) to 12,150 μg/m(3). For studies with all windows closed, PM2.5 ranged from 203.6 μg/m(3) to 13,150 μg/m(3). SHS concentration in a car was mediated by air-conditioning status, extent of airflow, and driving speed. Smoking in cars leads to extremely high exposure to SHS and increased concentration of atmospheric markers of exposure-even in the presence of air-conditioning or increased airflow from open windows. This clearly shows that the only way to protect nonsmokers, especially children, from SHS within cars is by eliminating tobacco smoking.

Resveratrol protects against functional impairment and cardiac structural protein degradation induced by secondhand smoke exposure

BACKGROUND

Secondhand smoke (SHS) impairs cardiac function and resveratrol is cardioprotective, possibly via antioxidant and anti-inflammatory capabilities. Previously, it was shown that resveratrol protects against SHS-induced cardiac dysfunction, but the molecular mechanism is not clear.

METHODS

We measured cardiac function in pigs exposed to SHS alone in a first experiment or with and without resveratrol (5 mg/kg/day) in a second experiment using echocardiography and compared this with proteomic changes.

RESULTS

In the first experiment after 28 days, end-diastolic volume, end-systolic volume, and stroke volume were all impaired in SHS pigs compared with control pigs, with cardiac output significantly depressed as early as 14 days. Depressed function corresponded to increased inflammation, oxidative stress, and matrix metalloproteinase-2, but decreased intact myosin light chain 1 in SHS compared with control pigs at 28 days. In our second study after 14 days, two-dimensional electrophoresis detected 6 significantly increased protein spots in SHS compared with control pigs. Mass spectrometry identified 4 spots as fragments of sarcomeric protein (1 myosin light chain 1, 1 β-myosin heavy chain, and 2 myosin-7), and 2 spots as glucose metabolism enzymes (lactate and pyruvate dehydrogenases). Resveratrol normalized the fragmented protein levels, but not the metabolic enzymes. At 14 days, matrix metalloproteinase-2 activity almost doubled in cardiac tissue from SHS compared with control pigs, and resveratrol appeared to normalize it.

CONCLUSIONS

Thus, the ventricular differences in protein expression might explain the mechanism by which SHS reduces critical hemodynamic parameters through the degradation of sarcomeres, appearing to be prevented by resveratrol administration.

Effects of residential indoor air quality and household ventilation on preterm birth and term low birth weight in Los Angeles County, California

OBJECTIVES

The purpose of our study was to examine the effects of indoor residential air quality on preterm birth and term low birth weight (LBW).

METHODS

We evaluated 1761 nonsmoking women from a case-control survey of mothers who delivered a baby in 2003 in Los Angeles County, California. In multinomial logistic regression models adjusted for maternal age, education, race/ethnicity, parity and birthplace, we evaluated the effects of living with smokers or using personal or household products that may contain volatile organic compounds and examined the influence of household ventilation.

RESULTS

Compared with unexposed mothers, women exposed to secondhand smoke (SHS) at home had increased odds of term LBW (adjusted odds ratio [OR] = 1.36; 95% confidence interval [CI] =  0.85, 2.18) and preterm birth (adjusted OR = 1.27; 95% CI = 0.95, 1.70), although 95% CIs included the null. No increase in risk was observed for SHS-exposed mothers reporting moderate or high window ventilation. Associations were also observed for product usage, but only for women reporting low or no window ventilation.

CONCLUSIONS

Residential window ventilation may mitigate the effects of indoor air pollution among pregnant women in Los Angeles County, California.

Particulate matter (PM) 2.5 levels in ETS emissions of a Marlboro Red cigarette in comparison to the 3R4F reference cigarette under open- and closed-door condition

INTRODUCTION

Potential health damage by environmental emission of tobacco smoke (environmental tobacco smoke, ETS) has been demonstrated convincingly in numerous studies. People, especially children, are still exposed to ETS in the small space of private cars. Although major amounts of toxic compounds from ETS are likely transported into the distal lung via particulate matter (PM), few studies have quantified the amount of PM in ETS.

STUDY AIM

The aim of this study was to determine the ETS-dependent concentration of PM from both a 3R4F reference cigarette (RC) as well as a Marlboro Red brand cigarette (MRC) in a small enclosed space under different conditions of ventilation to model car exposure.

METHOD

In order to create ETS reproducibly, an emitter (ETSE) was constructed and mounted on to an outdoor telephone booth with an inner volume of 1.75 m3. Cigarettes were smoked under open- and closed-door condition to imitate different ventilation scenarios. PM2.5 concentration was quantified by a laser aerosol spectrometer (Grimm; Model 1.109), and data were adjusted for baseline values. Simultaneously indoor and outdoor climate parameters were recorded. The time of smoking was divided into the ETS generation phase (subset "emission") and a declining phase of PM concentration (subset "elimination"); measurement was terminated after 10 min. For all three time periods the average concentration of PM2.5 (Cmean-PM2.5) and the area under the PM2.5 concentration curve (AUC-PM2.5) was calculated. The maximum concentration (Cmax-PM2.5) was taken from the total interval.

RESULTS

For both cigarette types open-door ventilation reduced the AUC-PM2.5 (RC: from 59 400 ± 14 600 to 5 550 ± 3 900 μg*sec/m3; MRC: from 86 500 ± 32 000 to 7 300 ± 2 400 μg*sec/m3; p < 0.001) and Cmean-PM2.5 (RC: from 600 ± 150 to 56 ± 40 μg/m3, MRC from 870 ± 320 to 75 ± 25 μg/m3; p < 0.001) by about 90%. Cmax-PM2.5 was reduced by about 80% (RC: from 1 050 ± 230 to 185 ± 125 μg/m3; MRC: from 1 560 ±500 μg/m3 to 250 ± 85 μg/m3; p < 0.001). In the subset "emission" we identified a 78% decrease in AUC-PM2.5 (RC: from 18 600 ± 4 600 to 4 000 ± 2 600 μg*sec/m3; MRC: from 26 600 ± 7 200 to 5 800 ± 1 700 μg*sec/m3; p < 0.001) and Cmean-PM2.5 (RC: from 430 ± 108 to 93 ± 60 μg/m3; MRC: from 620 ± 170 to 134 ± 40 μg/m3; p < 0.001). In the subset "elimination" we found a reduction of about 96-98% for AUC-PM2.5 (RC: from 40 800 ± 11 100 to 1 500 ± 1 700 μg*sec/m3; MRC: from 58 500 ± 25 200 to 1 400 ± 800 μg*sec/m3; p < 0.001) and Cmean-PM2.5 (RC: from 730 ± 200 to 27 ± 29 μg/m3; MRC: from 1 000 ± 450 to 26 ± 15 μg/m3; p < 0.001). Throughout the total interval Cmax-PM2.5 of MRC was about 50% higher (1 550 ± 500 μg/m3) compared to RC (1 050 ± 230 μg/m3; p < 0.05). For the subset "emission" - but not for the other periods - AUC-PM2.5 for MRC was 43% higher (MRC: 26 600 ± 7 200 μg*sec/m3; RC: 18 600 ± 4 600 μg*sec/m3; p < 0.05) and 44% higher for Cmean-PM2.5 (MRC: 620 ± 170 μg/m3; RC: 430 ± 108 μg/m3; p < 0.05).

CONCLUSION

This method allows reliable quantification of PM2.5-ETS exposure under various conditions, and may be useful for ETS risk assessment in realistic exposure situations. The findings demonstrate that open-door condition does not completely remove ETS from a defined indoor space of 1.75 m3. Because there is no safe level of ETS exposure ventilation is not adequate enough to prevent ETS exposure in confined spaces, e.g. private cars. Additionally, differences in the characteristics of cigarettes affect the amount of ETS particle emission and need to be clarified by ongoing investigations.

Car indoor air pollution - analysis of potential sources

The population of industrialized countries such as the United States or of countries from the European Union spends approximately more than one hour each day in vehicles. In this respect, numerous studies have so far addressed outdoor air pollution that arises from traffic. By contrast, only little is known about indoor air quality in vehicles and influences by non-vehicle sources.Therefore the present article aims to summarize recent studies that address i.e. particulate matter exposure. It can be stated that although there is a large amount of data present for outdoor air pollution, research in the area of indoor air quality in vehicles is still limited. Especially, knowledge on non-vehicular sources is missing. In this respect, an understanding of the effects and interactions of i.e. tobacco smoke under realistic automobile conditions should be achieved in future.