Unlocking the secrets: Volatile Organic Compounds (VOCs) and their devastating effects on lung cancer

Lung cancer (LCs) is still a serious health problem globally, with many incidences attributed to environmental triggers such as Volatile Organic Compounds (VOCs). VOCs are a broad class of compounds that can be released via various sources, including industrial operations, automobile emissions, and indoor air pollution. VOC exposure has been linked to an elevated risk of lung cancer via multiple routes. These chemicals can be chemically converted into hazardous intermediate molecules, resulting in DNA damage and genetic alterations. VOCs can also cause oxidative stress, inflammation, and a breakdown in the cellular protective antioxidant framework, all of which contribute to the growth of lung cancer. Moreover, VOCs have been reported to alter critical biological reactions such as cell growth, apoptosis, and angiogenesis, leading to tumor development and metastasis. Epidemiological investigations have found a link between certain VOCs and a higher probability of LCs. Benzene, formaldehyde, and polycyclic aromatic hydrocarbons (PAHs) are some of the most well-researched VOCs, with comprehensive data confirming their cancer-causing potential. Nevertheless, the possible health concerns linked with many more VOCs and their combined use remain unknown, necessitating further research. Identifying the toxicological consequences of VOCs in LCs is critical for establishing focused preventative tactics and therapeutic strategies. Better legislation and monitoring mechanisms can limit VOC contamination in occupational and environmental contexts, possibly reducing the prevalence of LCs. Developing VOC exposure indicators and analyzing their associations with genetic susceptibility characteristics may also aid in early identification and targeted therapies.

Assessment of Saudi Society's Awareness of the Hazards of Scented Candles and Air Fresheners

<b>Background and Objective:</b> Air fresheners and scented candles are dangerous for human health and the environment. They are associated with allergies and irritation for a weak respiratory system. This study was conducted to determine the extent of community awareness of the toxicity associated with scented candles and air fresheners. <b>Materials and Methods:</b> This study uses a questionnaire from March, 2023 to June, 2023. The study questionnaire, which was completed by 1667 participants, assesses the degree of knowledge, habits and diseases connected to scents and candles. Descriptive statistics, including percentages, were used. <b>Results:</b> It was discovered that, on average, 568 (34.1%) people are unaware that candles contain chemicals. As 1497 (89.8%) are prepared to replace them with natural and safer candles, while 163 (9.8%) consulted a doctor after exposure to candles because of respiratory allergies; 1093 (65.5%) do not care to check the ingredients before buying a candle and 854 (51.2%) are unaware that candles might cause long-term damage. <b>Conclusion:</b> A significant portion of participants were unaware of the dangers of scented candles and air fresheners. There is no link between respiratory allergies and the substances present in these candles, but it has been proven that most participants are ready to change and use natural alternatives.

Do Synthetic Fragrances in Personal Care and Household Products Impact Indoor Air Quality and Pose Health Risks?

Fragrance compounds (synthetic fragrances or natural essential oils) comprise formulations of specific combinations of individual materials or mixtures. Natural or synthetic scents are core constituents of personal care and household products (PCHPs) that impart attractiveness to the olfactory perception and disguise the unpleasant odor of the formula components of PCHPs. Fragrance chemicals have beneficial properties that allow their use in aromatherapy. However, because fragrances and formula constituents of PCHPs are volatile organic compounds (VOCs), vulnerable populations are exposed daily to variable indoor concentrations of these chemicals. Fragrance molecules may trigger various acute and chronic pathological conditions because of repetitive human exposure to indoor environments at home and workplaces. The negative impact of fragrance chemicals on human health includes cutaneous, respiratory, and systemic effects (e.g., headaches, asthma attacks, breathing difficulties, cardiovascular and neurological problems) and distress in workplaces. Pathologies related to synthetic perfumes are associated with allergic reactions (e.g., cutaneous and pulmonary hypersensitivity) and potentially with the perturbation of the endocrine-immune-neural axis. The present review aims to critically call attention to odorant VOCs, particularly synthetic fragrances and associated formula components of PCHPs, potentially impacting indoor air quality and negatively affecting human health.

Extent of exposure to scented candles and prevalence of respiratory and non-respiratory symptoms amongst young university students

BACKGROUND

Incense burning such as scented candles are commonly used in Arabian Gulf regions as it is thought to produce relaxing effects on people's mood. This study is conducted to examine the prevalence of scented candles' usage, extent of exposure and its effects on individuals' health based on symptoms prevalence in young university students.

MATERIAL AND METHOD

A cross-sectional study was conducted on university students from different regions in Saudi Arabia. Data was collected in March 2020 using an online questionnaire survey adapted from The European Community Respiratory Health Survey-II (ECRHS-II). Inclusion criterion for recruitment was students with non-smoking status. Descriptive statistics were used to report demographic data on the extent of exposure to scented candles (in terms of frequency and duration) and the presence of symptoms. Multiple logistic regression analysis was used to assess the relationship between scented candles exposure and respiratory and other health-related problems.

RESULTS

The prevalence of scented candles usage was 65.7% (472/718) among the respondents. However, its pervasiveness was significantly higher in females than in male respondents (74.9% vs. 28.4%; p = 0.0001). Among the scented candle users, 34.8% of the respondents used the scented candles more than 4 times a month and 40.2% of the respondents lit the scented candles for 20-40 min. A total of 117 (24.8%) respondents reported health-related problem and the top three health problems were headache 72 (15.2%), shortness of breath 42 (8.9%) and cough 37 (7.8%). The scented candle usage 5-6 times a week showed significantly lower wheezing (OR = 0.10, 95%CI 0.02-0.54, p = 0.008). The duration of more than 60 min of scented candle exposure showed higher occurrence of headache 1.42 times (95% CI = 0.68-2.96), sneezing 1.29 times (95% CI = 0.42-4.00) and wheezing 1.23 times (95% CI = 0.48-3.13), though the association was not significant.

CONCLUSION

The results show that scented candle usage is more prevalent among female university students in Saudi Arabia. The common health-related problems associated with scented candle exposure were headache, shortness of breath and coughing.

Effects of occupant behaviors on perceived dormitory air quality and sick building syndrome symptoms among female college students

We performed a cross-sectional survey of 2143 female students in a university in Tianjin, China regarding perceived air quality (PAQ) and sick building syndrome (SBS) symptoms in the student dormitory. The prevalence of general, mucosal, and skin symptoms was 22.1%, 21.9%, and 26.3%, respectively. The three most prevalent PAQ complaints were "dry air" (48.9% often), "stuffy odor" (18.2%), and "other unpleasant odors" (5.1%), and they were significant risk factors for 11-12 out of 12 SBS symptoms (adjusted odds ratios [AOR]: 1.6-5.8). Survey data of 1471 undergraduates, whose dorms were of uniform layout and furnishing, were used to further investigate the influences of occupancy level and occupant behaviors on PAQ and SBS symptoms. Frequent use of air freshener/perfume was a significant risk factor for "dry air," less frequent room cleaning and higher occupancy density were significant risk factors for "stuffy odor," and less natural ventilation was a significant risk factor for both "stuffy odor" and "pungent odor." These factors were also significantly associated with some SBS symptoms. In particular, the use of air freshener/perfume exhibited a significant dose-response pattern with "fatigue" (sometimes: AOR 1.3; often: AOR 2.0) and with "irritated, stuffy, or runny nose" (sometimes: AOR 1.6; often: AOR 2.2).

Relationships between House Characteristics and Exposures to Metal(loid)s and Synthetic Organic Contaminants Evaluated Using Settled Indoor Dust

This study investigates associations between house characteristics and chemical contaminants in house dust, collected under the nationally representative Canadian House Dust Study (2007−2010). Vacuum samples (<80 µm fraction) were analysed for over 200 synthetic organic compounds and metal(loid)s. Spearman rank correlations between contaminant concentrations in dust and presence of children and pets, types of flooring, heating styles and other characteristics suggested a number of indoor sources, pointing to future research directions. Numerous synthetic organics were significantly associated with reported use of room deodorizers and with the presence of cats in the home. Hardwood flooring, which is a manufactured wood product, emerged as a source of metal(loid)s, phthalates, organophosphate flame retardants/plasticizers, and obsolete organochlorine pesticides such as ∑DDT (but not halogenated flame retardants). Many metal(loid)s were significantly correlated with flame-retardant compounds used in building materials and heating systems. Components of heating appliances and heat distribution systems appeared to contribute heat-resistant chemicals and alloys to settled dust. Carpets displayed a dual role as both a source and repository of dust-borne contaminants. Contaminant loadings (<80 µm fraction) were significantly elevated in heavily carpeted homes, particularly those located near industry. Depending on the chemical (and its source), the results show that increased dust mass loading may enrich or dilute chemical concentrations in dust. Research is needed to improve the characterisation of hidden indoor sources such as flame retardants used in building materials and heating systems, or undisclosed ingredients used in common household products, such as air fresheners and products used for companion animals.

In-situ TD-GCMS measurements of oxidative products of monoterpenes at typical vaping temperatures: implications for inhalation exposure to vaping products

Vaping is gaining in popularity. However, there is still much that remains unknown about the potential risk and harms of vaping. Formation of oxidative products is one of such areas that are not well understood. In this study, we used an in-situ thermal desorption GC/MS method to investigate the formation of oxidative products of several monoterpenes at or below typical vaping temperatures. Among the five tested monoterpenes, the unchanged portion of the parent compound in the vapour varied from 97 to 98% for myrcene to 11–28% for terpinolene. The majority of formed oxidative products in the vapour have a molecular weight of 134 (loss of two hydrogens), 150 (insertion of one oxygen and loss of two hydrogen atoms) or 152 (insertion of one oxygen atom). Three products, likely to be p-(1-propenyl)-toluene, β-pinone and fenchol were also observed. This is the first in-situ thermal desorption GC/MS study to investigate the possible formation of oxidative products of monoterpenes, one of the major components in vaping liquids, at temperatures that are relevant to the vaping process. Although the toxicity of inhaling these oxidative products is not clear yet, allergic and irritation reactions associated with oxidized monoterpene oils are well documented. Therefore, potential adverse effects of inhaling these oxidative products during vaping could be investigated to help support human risk assessment.

Volatile organic compound and particulate emissions from the production and use of thermoplastic biocomposite 3D printing filaments

Biocomposites (BCs) can be used as substitutes for unsustainable polymers in 3D printing, but their safety demands additional investigation as biological fillers may produce altered emissions during thermal processing. Commercial filament extruders can be used to produce custom feedstocks, but they are another source of airborne contaminants and demand further research. These knowledge gaps are targeted in this study. Volatile organic compound (VOC), carbonyl compound, ultrafine particle (UFP), and fine (PM_2.5) and coarse (PM₁₀) particle air concentrations were measured in this study as a filament extruder and a 3D printer were operated under an office environment using one PLA and four PLA-based BC feedstocks. Estimates of emission rates (ERs) for total VOCs (TVOC) and UFPs were also calculated. VOCs were analyzed with a GC-MS system, carbonyls were analyzed with an LC-MS/MS system, whereas real-time particle concentrations were monitored with continuously operating instruments. VOC concentrations were low throughout the experiment; TVOC ranged between 34-63 µg/m³ during filament extrusion and 41-56 µg/m³ during 3D printing, which represent calculated TVOC ERs of 2.6‒3.6 × 10² and 2.9‒3.6 × 10² µg/min. Corresponding cumulative carbonyls ranged between 60-91 and 190-253 µg/m³. Lactide and miscellaneous acids and alcohols were the dominant VOCs, while acetone, 2-butanone, and formaldehyde were the dominant carbonyls. Terpenes contributed for ca. 20-40% of TVOC during BC processing. The average UFP levels produced by the filament extruder were 0.85 × 10²-1.05 × 10³ #/cm³, while the 3D printer generated 6.05 × 10²-2.09 × 10³ #/cm³ particle levels. Corresponding particle ERs were 5.3 × 10⁸-6.6 × 10⁹ and 3.8 × 10⁹-1.3 × 10¹⁰ #/min. PM_2.5 and PM₁₀ particles were produced in the following average quantities; PM_2.5 levels ranged between 0.2-2.2 µg/m³, while PM₁₀ levels were between 5-20 µg/m³ for all materials. The main difference between the pure PLA and BC feedstock emissions was terpenes, present during all BC extrusion processes. BCs are similar emission sources as pure plastics based on our findings, and a filament extruder produces contaminants at comparable or slightly lower levels in comparison to 3D printers.

Sprays and diffusers as indoor air fresheners: Exposure and health risk assessment based on measurements under realistic indoor conditions

Noncombustible air fresheners are indoor air emission sources of concern. The associated health risks should be better understood. Based on 15 products (4 sprays, 6 passive diffusers, and 5 active diffusers), the health risk assessment (HRA) approach was applied to a national use survey in France and to concentrations measured in an experimental house. The targeted substances included volatile organic compounds (VOCs), carbonyls, and fine particles (PM_2.5 ). Mean-use and reasonable worst-case generic scenarios were designed. No situation of concern occurred regarding chronic exposure associated with the mean use. Under the reasonable worst-case scenarios, the chronic risk could exceed selected health reference standards, mainly for acrolein (average inhaled concentration (AIC) up to 3.5 µg/m³ ), benzene (AIC up to 4 µg/m³ ), and limonene (AIC up to 8 mg/m³ ). The acute exposure, defined as a 1-h exposure, could exceed selected health standards, primarily for acrolein (up to 23 µg/m³ ) and formaldehyde (up to approximately 370 µg/m³ ). Furthermore, the 1-h average PM_2.5 concentration, including ultrafine particles, could exceed 100 µg/m³ , typically for sprays. These results suggest that the highest exposures should be reduced and, as such, that the emissions of the highest-emissivity products should be lowered.

Volatile organic compound and particulate matter emissions from an ultrasonic essential oil diffuser

Ultrasonic essential oil diffusers (EODs) are a popular type of indoor scenting source. We performed a chamber study in which we measured the emissions from EODs used with lemon, lavender, eucalyptus, and grapeseed oils. Over the course of 15 min, the most abundant VOCs released from lemon, lavender, eucalyptus, and grapeseed oils were 2.6 ± 0.7 mg of d-limonene, 3.5 ± 0.4 mg of eucalyptol, 1.0 ± 0.1 mg of linalyl acetate, and 0.2 ± 0.02 mg of linalyl acetate, respectively. Each oil had a unique particulate matter (PM) emission profile in terms of size, number density, and rate. The dominant size ranges of the PM were 10-100 nm for lemon oil, 50-100 nm for lavender oil, 10-50 nm for lemon oil, and above 200 nm for grapeseed oil. PM₁ emission rates of approximately 2 mg/h, 0.1 mg/h, and 3 mg/h, were observed for lemon, lavender/eucalyptus, and grapeseed oils, respectively. A fivefold increase in PM₁ emission was measured when the EOD with eucalyptus oil was filled with tap water as opposed to deionized water. Modeling suggests that reasonable use cases of EODs can contribute substantially to primary and secondary PM in indoor environments, but this potential varies depending on the oil and water types used.

Real-time molecular characterization of air pollutants in a Hong Kong residence: Implication of indoor source emissions and heterogeneous chemistry

Due to the high health risks associated with indoor air pollutants and long-term exposure, indoor air quality has received increasing attention. In this study, we put emphasis on the molecular composition, source emissions, and chemical aging of air pollutants in a residence with designed activities mimicking ordinary Hong Kong homes. More than 150 air pollutants were detected at molecular level, 87 of which were quantified at a time resolution of not less than 1 hour. The indoor-to-outdoor ratios were higher than 1 for most of the primary air pollutants, due to emissions of indoor activities and indoor backgrounds (especially for aldehydes). In contrast, many secondary air pollutants exhibited higher concentrations in outdoor air. Painting ranked first in aldehyde emissions, which also caused great enhancement of aromatics. Incense burning had the highest emissions of particle-phase organics, with vanillic acid and syringic acid as markers. The other noteworthy fingerprints enabled by online measurements included linoleic acid, cholesterol, and oleic acid for cooking, 2,5-dimethylfuran, stigmasterol, iso-/anteiso-alkanes, and fructose isomers for smoking, C₂₈ -C₃₄ even n-alkanes for candle burning, and monoterpenes for the use of air freshener, cleaning agents, and camphor oil. We showed clear evidence of chemical aging of cooking emissions, giving a hint of indoor heterogeneous chemistry. This study highlights the value of organic molecules measured at high time resolutions in enhancing our knowledge on indoor air quality.

Environmental Health-Related Policies and Practices of Oklahoma Licensed Early Care and Education Programs: Implications for Childhood Asthma

Little is known about the environmental health-related policies and practices of early care and education (ECE) programs that contribute to childhood asthma, particularly in Oklahoma where child asthma rates (9.8%) and rates of uncontrolled asthma among children with asthma (60.0%) surpass national rates (8.1% and 50.3%, respectively). We conducted a cross-sectional survey with directors of Oklahoma-licensed ECE programs to assess policies and practices related to asthma control and to evaluate potential differences between Centers and Family Childcare Homes (FCCHs). Surveyed ECEs (n = 476) included Centers (56.7%), FCCHs (40.6%), and other program types (2.7%). Almost half (47.2%) of directors reported never receiving any asthma training. More Center directors were asthma-trained than FCCH directors (61.0% versus 42.0%, p < 0.0001). Most ECEs used asthma triggers, including bleach (88.5%) and air fresheners (73.6%). Centers were more likely to use bleach daily than were FCCHs (75.6% versus 66.8%, p = 0.04). FCCHs used air fresheners more than did Centers (79.0% versus 61.0%, p < 0.0001). The majority of ECEs (74.8%) used pesticides indoors. Centers applied indoor pesticides more frequently (i.e., monthly or more often) than did FCCHs (86.0% versus 58.0%, p < 0.0001). Policy, educational, and technical assistance interventions are needed to reduce asthma triggers and improve asthma control in Oklahoma ECEs.

Inhaled exposure to air fresheners aggravated liver injury in a murine model of nonalcoholic fatty acid liver disease

At present, the consumption and use of air fresheners (AFs) is rapidly increasing worldwide for the purposes of odor removal and to create a pleasant odor. Many recent studies have strongly suggested that the potentially hazardous chemicals emitted from AFs may be the primary source of indoor air pollutants and may cause adverse health effects. Despite the presence of hazardous chemicals in AFs, potential adverse health effects and risk assessment of AFs have not yet been established. The incidence of nonalcoholic fatty acid liver disease (NAFLD) around the world is rapidly increasing, as with obesity and diabetes, and is one of the most common causes of liver disease worldwide. Based on the demonstrated evidence that NAFLD could eventually develop into further health complications such as liver failure, cardiovascular disease, liver cirrhosis, or liver cancer, the current study was performed to clarify the relationship between inhaled AF exposure and NAFLD using a high-fructose diet (HFr)-induced murine model. The results from current study clearly demonstrated that AF exposure further exacerbated liver injury in NAFLD-induced mice. Interestingly, the increased expression of fibrosis-related factors and collagen accumulation in the liver of AF-exposed NAFLD-induced mice resulted in nonalcoholic steatohepatitis (NASH)-like phenotype and fibrosis. Taken together, these results strongly suggest that AF exposure may not only induce liver injury but may also exacerbate NAFLD to lead to NASH-like symptoms. Further study is needed to shed light on the detailed mechanisms behind AF-induced liver effects and its potential role in exacerbating NAFLD to more detrimental disease in order to better scientific evidence for risk assessments of indoor AF exposure.

Health effects of wildfire smoke in children and public health tools: a narrative review

Wildfire smoke is an increasing environmental health threat to which children are particularly vulnerable, for both physiologic and behavioral reasons. To address the need for improved public health messaging this review summarizes current knowledge and knowledge gaps in the health effects of wildfire smoke in children, as well as tools for public health response aimed at children, including consideration of low-cost sensor data, respirators, and exposures in school environments. There is an established literature of health effects in children from components of ambient air pollution, which are also present in wildfire smoke, and an emerging literature on the effects of wildfire smoke, particularly for respiratory outcomes. Low-cost particulate sensors demonstrate the spatial variability of pollution, including wildfire smoke, where children live and play. Surgical masks and respirators can provide limited protection for children during wildfire events, with expected decreases of roughly 20%  and 80% for surgical masks and N95 respirators, respectively. Schools should improve filtration to reduce exposure of our nation's children to smoke during wildfire events. The evidence base described may help clinical and public health authorities provide accurate information to families to improve their decision making.

Buckwheat, rooibos, and vitex extracts can mitigate adverse effects of xylene on ovarian cells in vitro

This study examines whether selected functional food and medicinal plants can mitigate the adverse effects of xylene on ovarian cells. The influences of xylene (0, 10, 100, or 1000 ng/mL), buckwheat (Fagopyrum esculentum), rooibos (Aspalathus linearis), vitex (Vitex agnus-castus), extracts (10 μg/mL each), and a combination of xylene with these plant additives on cultured porcine ovarian granulosa cells are compared. Cell viability, proliferation (PCNA accumulation), apoptosis (accumulation of bax), and release of progesterone (P4) and estradiol (E2) were analyzed by the trypan blue tests, quantitative immunocytochemistry, and enzyme-linked immunosorbent assays, respectively. Xylene suppressed all measures of ovarian cell function. Rooibos prevented all of xylene's effects, whereas buckwheat and vitex prevented four of five of the analyzed effects (buckwheat prevented xylene influence on viability, PCNA, bax, and E2; vitex prevented xylene action on viability, PCNA, and P4 and E2). These observations show that xylene has the potential to suppress ovarian cell functions, and that buckwheat, rooibos, and vitex can mitigate those effects, making them natural protectors against the adverse effects of xylene on ovarian cells.

Real-time indoor PM2.5 monitoring in an urban cohort: Implications for exposure disparities and source control

Fine particulate matter (PM2.5) concentrations are highly variable indoors, with evidence for exposure disparities. Real-time monitoring coupled with novel statistical approaches can better characterize drivers of elevated PM2.5 indoors. We collected real-time PM2.5 data in 71 homes in an urban community of Greater Boston, Massachusetts using Alphasense OPC-N2 monitors. We estimated indoor PM2.5 concentrations of non-ambient origin using mass balance principles, and investigated their associations with indoor source activities at the 0.50 to 0.95 exposure quantiles using mixed effects quantile regressions, overall and by homeownership. On average, the majority of indoor PM2.5 concentrations were of non-ambient origin (≥77%), with a higher proportion at increasing quantiles of the exposure distribution. Major source predictors of non-ambient PM2.5 concentrations at the upper quantile (0.95) were cooking (1.4-23 μg/m3) and smoking (15 μg/m3, only among renters), with concentrations also increasing with range hood use (3.6 μg/m3) and during the heating season (5.6 μg/m3). Across quantiles, renters in multifamily housing experienced a higher proportion of PM2.5 concentrations from non-ambient sources than homeowners in single- and multifamily housing. Renters also more frequently reported cooking, smoking, spray air freshener use, and second-hand smoke exposure, and lived in units with higher air exchange rate and building density. Accounting for these factors explained observed PM2.5 exposure disparities by homeownership, particularly in the upper exposure quantiles. Our results suggest that renters in multifamily housing may experience higher PM2.5 exposures due to a combination of behavioral and building factors that are amenable to intervention.

Respiratory health effects of residential individual and cumulative risk factors in children living in two cities of the Pearl River Delta Region, China

Background

Indoor environment is complex, with many factors potentially interacting with each other to affect health. However, previous studies have usually focused on effect of a single factor. Assessment of the combined effects of multiple factors can help with understanding the overall health risk.

Methods

A cross-sectional study was conducted among 2,306 school children in Guangzhou and Shenzhen. Questionnaire data on respiratory symptoms and diseases were collected along with sociodemographic and residential environmental information. A subset of children (N=987) were measured for their lung function. A random forest algorithm was applied to screen the top-ranked indoor environmental exposure variables and to form a composite index for cumulative risk of indoor pollution (CRIP). Logistic regressions were conducted to analyze the independent effect of single indoor environmental risk factors and the combined effect of CRIP on children’s respiratory health. Multiple linear regressions were used to examine the independent and combined effects of indoor environmental exposure on lung function.

Results

We found that home dampness and molds as well as environmental tobacco smoke (ETS) were significantly and independently associated with increased prevalence of children’s respiratory symptoms and diseases and with reduced lung function. A higher CRIP level was significantly associated with increased risk of cough with cold (OR =1.37, 95% CI: 1.05–1.79) and wheeze (OR =2.71, 95% CI: 1.16–6.34). A higher CRIP level was also associated with reduced lung function measured as FVC, FEV₁, PEF, FEF_25%, FEF_25–75% and VC.

Conclusions

In children living in the subtropical region of the Pearl River Delta, home dampness and the presence of mold as well as ETS were individual risk factors for children’s respiratory health. The composite CRIP index was associated with respiratory symptoms and lung function, suggesting the utility of this index for predicting the combined effects of multiple risk factors.

Bad Air Can Also Kill: Residential Indoor Air Quality and Pollutant Exposure Risk during the COVID-19 Crisis

During the first outbreak of the SARS-CoV-2 pandemic the population, focusing primarily on the risk of infection, was generally inattentive to the quality of indoor air. Spain, and the city of Madrid in particular, were among the world's coronavirus hotspots. The country's entire population was subject to a 24/7 lockdown for 45 days. This paper describes a comparative longitudinal survey of air quality in four types of housing in the city of Madrid before and during lockdown. The paper analysed indoor temperatures and variations in CO2, 2.5 μm particulate matter (PM2.5) and total volatile organic compound (TVOC) concentrations before and during lockdown. The mean daily outdoor PM2.5 concentration declined from 11.04 µg/m3 before to 7.10 µg/m3 during lockdown. Before lockdown the NO2 concentration values scored as 'very good' 46% of the time, compared to 90.9% during that period. Although the city's outdoor air quality improved, during lockdown the population's exposure to indoor pollutants was generally more acute and prolonged. Due primarily to concern over domestic energy savings, the lack of suitable ventilation and more intensive use of cleaning products and disinfectants during the covid-19 crisis, indoor pollutant levels were typically higher than compatible with healthy environments. Mean daily PM2.5 concentration rose by approximately 12% and mean TVOC concentration by 37% to 559%. The paper also puts forward a series of recommendations to improve indoor domestic environments in future pandemics and spells out urgent action to be taken around indoor air quality (IAQ) in the event of total or partial quarantining to protect residents from respiratory ailments and concomitantly enhanced susceptibility to SARS-CoV-2, as identified by international medical research.

Associations of urinary di-(2-ethylhexyl) phthalate metabolites with the residential characteristics of pregnant women

Epidemiological evidence on the associations between urinary di-(2-ethylhexyl) phthalate (DEHP) metabolites and residential characteristics is limited. Therefore, we investigated the associations of urinary DEHP metabolites with the residential characteristics of pregnant women. We collected completed questionnaires and maternal spot urine samples from 616 random pregnant women in Shengjing Hospital of China Medical University in Shenyang. Urinary DEHP metabolites concentrations, including mono-(2-ethylhexyl) phthalate (MEHP) and mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), were measured and analyzed by Gas Chromatography-Mass Spectrometry (GC-MS). Multivariable linear regression models were performed to obtain regression estimates (β) and 95% confidence intervals (CIs) after adjustment for sociodemographic characteristics. In all participants, the geometric mean of MEHP and MEHHP concentrations were 4.25 ± 4.34 and 5.72 ± 2.65 μg/L, respectively. In multivariable analyses after adjusting for sociodemographic characteristics, distance from residence to motor vehicle traffic (≥150 m versus <20 m) was negatively associated with MEHP (β = -0.241, 95% CI: -0.448, -0.033) and MEHHP (β = -0.279, 95% CI: -0.418, -0.140) concentrations. Compared with the one that had not recently been renovated, a renovated home was associated with higher MEHP (β = 0.194, 95% CI: 0.064, 0.324) and MEHHP (β = 0.111, 95% CI: 0.024, 0.197) concentrations. Air freshener use was associated with higher MEHP (β = 0.322, 95% CI: 0.007, 0.636) concentrations. Moldy walls were positively associated with MEHP (β = 0.299, 95% CI: 0.115, 0.482) and MEHHP (β = 0.172, 95% CI: 0.050, 0.294) concentrations. In contrast, humidifier use was associated with a lower MEHP concentration (β = -0.167, 95% CI: -0.302, -0.032). Residential characteristics were probably associated with the DEHP exposure of pregnant women in Shenyang. Living near the motor vehicle traffic, residential renovation, air freshener use, and moldy walls are likely risk factors for increased DEHP exposure, whereas using household humidifier could be considered a protective measure to reduce DEHP exposure.

Sources of volatile organic compounds in suburban homes in Shanghai, China, and the impact of air filtration on compound concentrations

Air pollution in China is an ongoing concern, with subsets of the population (e.g., asthmatic children) especially susceptible to the associated health effects. In addition, people spend the majority of their time indoors, where pollutant composition may differ from the better characterized ambient environment. Although volatile organic compounds (VOCs) present health risks and have high concentrations indoors, their sources have not been thoroughly quantified in typical homes in suburban China. Similarly lacking is an understanding of how well a purifier with high efficiency particulate air and activated carbon filters can remove VOCs in a real-world setting in China. In this study, we a) quantified total VOCs (TVOC) and 900 + individual VOCs in 20 homes in China, b) identified potential sources of VOCs, and c) evaluated impacts of filtration. We used non-negative matrix factorization, a variable reduction technique, to identify sources. TVOC and individual compounds had higher concentrations indoors than outdoors (mean [range] indoors, filtration with pre-filter only: 302 [56-793] μg m-3; outdoors, entire study: 92 [26-629] μg m-3), indicating prevalent sources indoors. Many compounds detected have not, to our knowledge, been measured in homes in China. Some compounds (e.g., octanal, heptanal, ⍺-cedrene) were specific to the indoor environment, a few were ubiquitous (e.g., acetaldehyde, formaldehyde), and others were detected infrequently. These compounds may originate from consumer products, solvents, vehicle emissions, a hexane source, wooden products, and cooking. Filtration may improve air quality indoors by lowering concentrations of some VOCs, and, specifically, contributions related to solvents and consumer products.

Understanding environmental contributions to autism: Causal concepts and the state of science

The complexity of neurodevelopment, the rapidity of early neurogenesis, and over 100 years of research identifying environmental influences on neurodevelopment serve as backdrop to understanding factors that influence risk and severity of autism spectrum disorder (ASD). This Keynote Lecture, delivered at the May 2016 annual meeting of the International Society for Autism Research, describes concepts of causation, outlines the trajectory of research on nongenetic factors beginning in the 1960s, and briefly reviews the current state of this science. Causal concepts are introduced, including root causes; pitfalls in interpreting time trends as clues to etiologic factors; susceptible time windows for exposure; and implications of a multi-factorial model of ASD. An historical background presents early research into the origins of ASD. The epidemiologic literature from the last fifteen years is briefly but critically reviewed for potential roles of, for example, air pollution, pesticides, plastics, prenatal vitamins, lifestyle and family factors, and maternal obstetric and metabolic conditions during her pregnancy. Three examples from the case-control CHildhood Autism Risks from Genes and the Environment Study are probed to illustrate methodological approaches to central challenges in observational studies: capturing environmental exposure; causal inference when a randomized controlled clinical trial is either unethical or infeasible; and the integration of genetic, epigenetic, and environmental influences on development. We conclude with reflections on future directions, including exposomics, new technologies, the microbiome, gene-by-environment interaction in the era of -omics, and epigenetics as the interface of those two. As the environment is malleable, this research advances the goal of a productive and fulfilling life for all children, teen-agers and adults. Autism Res 2018, 11: 554-586. © 2018 International Society for Autism Research, Wiley Periodicals, Inc.

LAY SUMMARY

This Keynote Lecture, delivered at the 2016 meeting of the International Society for Autism Research, discusses evidence from human epidemiologic studies of prenatal factors contributing to autism, such as pesticides, maternal nutrition and her health. There is no single cause for autism. Examples highlight the features of a high-quality epidemiology study, and what comprises a compelling case for causation. Emergent research directions hold promise for identifying potential interventions to reduce disabilities, enhance giftedness, and improve lives of those with ASD.

Temporal evolution of ultrafine particles and of alveolar deposited surface area from main indoor combustion and non-combustion sources in a model room

Aerosol number size distributions, PM mass concentrations, alveolar deposited surface areas (ADSAs) and VOC concentrations were measured in a model room when aerosol was emitted by sources frequently encountered in indoor environments. Both combustion and non-combustion sources were considered. The most intense aerosol emission occurred when combustion sources were active (as high as 4.1×10⁷particlescm^-3 for two meat grilling sessions; the first with exhaust ventilation, the second without). An intense spike generation of nucleation particles occurred when appliances equipped with brush electric motors were operating (as high as 10⁶particlescm^-3 on switching on an electric drill). Average UFP increments over the background value were highest for electric appliances (5-12%) and lowest for combustion sources (as low as -24% for tobacco cigarette smoke). In contrast, average increments in ADSA were highest for combustion sources (as high as 3.2×10³μm²cm^-3 for meat grilling without exhaust ventilation) and lowest for electric appliances (20-90μm²cm^-3). The health relevance of such particles is associated to their ability to penetrate cellular structures and elicit inflammatory effects mediated through oxidative stress in a way dependent on their surface area. The highest VOC concentrations were measured (PID probe) for cigarette smoke (8ppm) and spray air freshener (10ppm). The highest PM mass concentration (PM₁) was measured for citronella candle burning (as high as 7.6mgm^-3).

Emission characteristics of allergenic terpenols in PM2.5 released from incense burning and the effect of light on the emissions

This study investigated allergenic terpenol compounds in incense powder and smoke. The powder of two Thai brands contained higher concentrations of terpenols up to 6.15 times higher than those of two Taiwanese brands. Consequently, Thai incense makers face a higher potential risk of contact dermatitis than Taiwanese incense makers do. d-Limonene was the primary terpenol compound in the powder of Thai B (64.0%) and Thai Y (31.5%), sold in Thailand. By contrast, anisyl alcohol was the primary terpenol compound in the powder of LST (40.3%) and SC (37.7%), sold in Taiwan. After the four brands of incense were ignited, their mean PM_2.5 emission factor was 18.02±6.20mgg^-1 incense. The PM_2.5 mass emission factors of the Taiwanese brands were far higher than those of the Thai brands, and so were the PM_2.5 terpenol emission factors, showing that the smokes of the Taiwanese incense were potentially more allergenic than those of the Thai incense. Geraniol, the most allergenic terpenol compound, was 2.8%-10.7% of total terpenol compounds in the powder of the four brands, yet was the main contributor to PM_2.5, constituting 66.3%-83.5% of terpenol compounds in the smokes of the four brands. Furthermore, geraniol exhibited an IP ratio, defined as the incense/powder (IP) ratio of terpenol-related species, >1 in all four brands, and >5 in the Taiwanese brands, suggesting a greater health risk with the smoke from the Taiwanese incense. The IP ratios of other terpenol species were all <1, indicating decomposition through combustion. Additionally, the light/darkroom ratios of the terpenol species were >1, meaning that the generation of PM_2.5 terpenol compounds was potentially enhanced by indoor lighting.

Food consumption survey of Shanghai adults in 2012 and its associations with phthalate metabolites in urine

BACKGROUND

Diet is considered to be a significant exposure pathway for phthalates. In this study, we assessed the associations between food consumption and urinary concentrations of phthalate metabolites among Shanghai adults.

METHODS

A cross-sectional study involving 2418 participants was conducted in the fall of 2012. Recent food consumption was assessed by a 24-h dietary recall survey, and a Food Frequency Questionnaire (FFQ) characterized long-term dietary patterns. Urinary metabolites of six phthalates were measured.

RESULTS

Both the 24-h recall survey and FFQ identified wheat, dairy, and fruits as being positively associated with the excretion of phthalate metabolites. The 24-h recall data also showed positive associations with processed meats and alcohol. We evaluated the impact of reported consumption of multiple food categories simultaneously (wheat, fruits, meats, etc.) on metabolite excretion and found that, as more food types were consumed, the number of metabolites excreted, as well as their concentrations, increased with high significance (p values<0.0001). We also evaluated the two survey instruments together. When both surveys reported consumption of fruits and dairy, the numbers of metabolites and their concentrations were significantly higher compared to when both surveys reported non-consumption, (p values<0.000001). Rice consumption was found to be negatively associated with phthalate excretion; frequent and high levels of rice consumption were found to be associated with lower excretion of metabolites.

CONCLUSION

Food consumption was associated with phthalate exposure in Shanghai adults. Both 24-h recall and FFQ identified significant associations between consumption of food types and phthalate exposure.

Fragrances and work-related asthma-California surveillance data, 1993-2012

OBJECTIVE

Fragrance chemicals are used in a large array of products. Workers may be exposed to these chemicals in the workplace directly when used as air fresheners, or indirectly in personal care products used by coworkers or others. This study characterizes work-related asthma (WRA) cases associated with fragrance exposures in California workplaces from 1993 through 2012.

METHODS

We used the California Work-Related Asthma Prevention Program's surveillance database to identify individuals with physician-diagnosed WRA associated with the use of air fresheners and scented personal care products (perfumes, colognes, etc.). Cases were classified using previously published, standardized surveillance methods.

RESULTS

Perfume was the ninth most common exposure identified from 1993 through 2012. A total of 270 WRA cases associated with fragrance exposure were reported during this period, representing 3.8% of all confirmed cases. These 270 cases included 242 associated with perfume or cologne, 32 associated with air freshener, and 4 associated with both. Similar to non-fragrance cases, nearly a quarter of fragrance-associated cases were classified as new-onset asthma. Fragrance-associated cases were significantly more likely to be in office, health, and education jobs than non-fragrance-associated cases. When compared to non-fragrance cases, fragrance cases were significantly more likely to be female (94% vs 62%) and be classified as having work-aggravated asthma (38% vs 20%), yet had similar outcomes compared with cases associated with other exposures.

CONCLUSIONS

Our surveillance data show that fragrance use in the workplace is associated with WRA. Prevention methods include employee education, enforced fragrance-free policies, well-designed ventilation systems, and good building maintenance.

'Every breath we take: the lifelong impact of air pollution' - a call for action

Air pollution has become one of the major risks to human health because of the progressive increase in the use of vehicles powered by fossil fuels. While the risks of air pollution to health were thought to have been brought under control by the Clean Air Acts of the 1950s and 1960s, the situation of air pollution in the UK has now deteriorated to a point where it is contributing to 40,000 excess deaths each year. Here the findings of the RCP/RCPCH's 2015/16 Working Party on Air Pollution and Health are described and what actions now need to be taken. The UK needs to take a lead and introduce a new Clean Air Act that deals with the vehicle sources of pollution recognising that the toxic particles and gases emitted are effecting individuals from conception to death. This mandates urgent action by government both central and local, but also by all of us who have now become so dependent on road transport.

Exposure of BALB/c Mice to Diesel Engine Exhaust Origin Secondary Organic Aerosol (DE-SOA) during the Developmental Stages Impairs the Social Behavior in Adult Life of the Males

Secondary organic aerosol (SOA) is a component of particulate matter (PM) 2.5 and formed in the atmosphere by oxidation of volatile organic compounds. Recently, we have reported that inhalation exposure to diesel engine exhaust (DE) originated SOA (DE-SOA) affect novel object recognition ability and impair maternal behavior in adult mice. However, it is not clear whether early life exposure to SOA during the developmental stages affect social behavior in adult life or not. In the present study, to investigate the effects of early life exposure to DE-SOA during the gestational and lactation stages on the social behavior in the adult life, BALB/c mice were exposed to clean air (control), DE, DE-SOA and gas without any PM in the inhalation chambers from gestational day 14 to postnatal day 21 for 5 h a day and 5 days per week. Then adult mice were examined for changes in their social behavior at the age of 13 week by a sociability and social novelty preference, social interaction with a juvenile mouse and light-dark transition test, hypothalamic mRNA expression levels of social behavior-related genes, estrogen receptor-alpha and oxytocin receptor as well as of the oxidative stress marker gene, heme oxygenase (HO)-1 by real-time RT-PCR method. In addition, hypothalamic level of neuronal excitatory marker, glutamate was determined by ELISA method. We observed that sociability and social novelty preference as well as social interaction were remarkably impaired, expression levels of estrogen receptor-alpha, oxytocin receptor mRNAs were significantly decreased, expression levels of HO-1 mRNAs and glutamate levels were significantly increased in adult male mice exposed to DE-SOA compared to the control ones. Findings of this study indicate early life exposure of BALB/c mice to DE-SOA may affect their late-onset hypothalamic expression of social behavior related genes, trigger neurotoxicity and impair social behavior in the males.

Fragranced consumer products: exposures and effects from emissions

Fragranced consumer products, such as cleaning supplies, air fresheners, and personal care products, are a primary source of indoor air pollutants and personal exposure. Previous research indicates that fragranced products can trigger adverse health effects, with implications for workplaces and public places. This is the first study to examine the multiple dimensions of exposures related to fragranced products and effects in the US population. The study investigated the prevalence and types of fragranced product exposures, associated health effects, awareness of product emissions, and preferences for fragrance-free policies and environments. Data were collected using an online survey with a nationally representative population (n = 1136) of adults in the USA. Overall, 34.7 % of the population reported health problems, such as migraine headaches and respiratory difficulties, when exposed to fragranced products. Further, 15.1 % have lost workdays or a job due to fragranced product exposure in the workplace. Also, 20.2 % would enter a business but then leave as quickly as possible if they smell air fresheners or some fragranced product. Over 50 % of the population would prefer that workplaces, health care facilities and professionals, hotels, and airplanes were fragrance-free. While prior research found that common fragranced products, even those called green and organic, emitted hazardous air pollutants, more than two thirds of the population were not aware of this, and over 60 % would not continue to use a fragranced product if they knew it emitted such pollutants. Results from this study provide strong evidence that fragranced products can trigger adverse health effects in the general population. The study also indicates that reducing exposure to fragranced products, such as through fragrance-free policies, can provide cost-effective and relatively simple ways to reduce risks and improve air quality and health.

Indoor Air Pollutant Exposure for Life Cycle Assessment: Regional Health Impact Factors for Households

Human exposure to indoor pollutant concentrations is receiving increasing interest in Life Cycle Assessment (LCA). We address this issue by incorporating an indoor compartment into the USEtox model, as well as by providing recommended parameter values for households in four different regions of the world differing geographically, economically, and socially. With these parameter values, intake fractions and comparative toxicity potentials for indoor emissions of dwellings for different air tightness levels were calculated. The resulting intake fractions for indoor exposure vary by 2 orders of magnitude, due to the variability of ventilation rate, building occupation, and volume. To compare health impacts as a result of indoor exposure with those from outdoor exposure, the indoor exposure characterization factors determined with the modified USEtox model were applied in a case study on cooking in non-OECD countries. This study demonstrates the appropriateness and significance of integrating indoor environments into LCA, which ensures a more holistic account of all exposure environments and allows for a better accountability of health impacts. The model, intake fractions, and characterization factors are made available for use in standard LCA studies via www.usetox.org and in standard LCA software.