Airborne Volatile Organic Compounds Research Articles

How safe are 3D-printed skull models for neurosurgical simulation? Measurement of airborne particles and VOCs while burr hole drilling

PurposeThree-dimensional (3D)printed skulls for neurosurgical training are increasingly being used due to the widespread access to 3D printing technology, their low cost and accuracy, as well as limitations and ethical concerns associated with using human cadavers. However, little is known about the risks of airborne particles or volatile organic compounds (VOCs) released while drilling into 3D-printed plastic models. The aim of this study is to assess the level of exposure to airborne contaminants while burr hole drilling.Design/methodology/approach3D-printed skull samples were produced using three different materials (polyethylene terephthalate glycol [PETG], white resin and BoneSTN) across three different 3D print processes (fused filament fabrication, stereolithography [SLA] and material jetting). A neurosurgeon performed extended burr hole drilling for 10 min on each sample. Spot measurements of particulate matter (PM2.5 and PM10) were recorded, and air samples were analysed for approximately 90 VOCs.FindingsThe particulate matter for PETG was found to be below the threshold value for respirable particles. However, the particulate matter for white resin and BoneSTN was found to be above the threshold value at PM10, which could be harmful for long periods of exposure without personal protective equipment (PPE). The VOC measurements for all materials were found to be below safety thresholds, and therefore not harmful.Originality/valueTo the best of the authors’ knowledge, this is the first study to evaluate the safety of 3D-printed materials for burr hole surgical drilling. It recommends PETG as a safe material requiring minimal respiratory control measures, whereas resin-based materials will require safety controls to deal with airborne particles.

Ozone-assisted degradation of 2-methoxyethanol in a prototype plug flow photocatalytic reactor

Airborne volatile organic compounds (VOCs) present an increasingly relevant health hazard addressed by the EU directive 2016/2284 requiring 40-% reduction in emissions of non-methane VOCs by 2030 in comparison to 2005. Advanced oxidation processes (AOPs) provide a solution for the VOC problem in industry. Among AOPs, pulsed corona discharge (PCD) and photocatalytic oxidation (PCO) are of particular interest in their synergy complementing each other’s strengths in energy-efficient manner. In the present study, air polluted with 2-methoxyethanol (2ME) was treated by using a prototype 21.3 L photocatalytic reactor for the pollutant degradation at its variable concentrations (6–50 ppm), irradiances (65–119 W m−2) and residence times (12–77 sec). Further combination of PCO reactor with forthcoming PCD requires studies in ozone photocatalytic degradation as a standalone byproduct and in combination with 2ME. The analysis of variable conditions resulted in singling out the PCO major restrictive parameters, also demonstrating the degradation enhancement, when both 2ME and ozone were present in air. The PCO treatment combined with ozone resulted in degradation of 2ME and ozone for 40 % and 95 %, respectively.

The public-health significance of far-UVC-induced indoor ozone and its associated secondary chemistry.

There has been much recent interest in whole-room far-UVC (wavelength around 222 nm) to markedly and safely reduce overall levels of airborne pathogens in occupied indoor locations. Far-UVC light produces very low levels of ozone-in real-world scenarios induced ozone levels of less than 10 ppb, and much less in moderately or well-ventilated rooms compliant with US far-UVC dose recommendations, and very much less in rooms compliant with international far-UVC dose standards. At these very low ozone levels, there is no epidemiological evidence of increased health risks from any of the very large outdoor ozone studies, whether from ozone alone or from ozone plus associated pollutants. Indoors, at the low ozone concentrations of relevance here, ozone does not react rapidly enough with preexisting airborne volatile organic compounds to compete with even extremely low levels of room ventilation, so significant ozone-induced ultrafine particle production is very unlikely. Direct measurements in real-life room scenarios are consistent with these conclusions. A potential exception is the cleaning material limonene, which has an unusually high ozone interaction cross-section; in the far-UVC context, turning off far-UVC lights during cleaning with limonene products would be reasonable.

Talking Different Languages: The Role of Plant-Plant Communication When an Invader Beats up a Strange Neighborhood.

Communication through airborne volatile organic compounds (VOCs) and root exudates plays a vital role in the multifarious interactions of plants. Common ragweed (Ambrosia artemesiifolia L.) is one of the most troublesome invasive alien species in agriculture. Below- and aboveground chemical interactions of ragweed with crops might be an important factor in the invasive species' success in agriculture. In laboratory experiments, we investigated the contribution of intra- and interspecific airborne VOCs and root exudates of ragweed to its competitiveness. Wheat, soybean, and maize were exposed to VOCs emitted from ragweed and vice versa, and the adaptation response was measured through plant morphological and physiological traits. We observed significant changes in plant traits of crops in response to ragweed VOCs, characterized by lower biomass production, lower specific leaf area, or higher chlorophyll contents. After exposure to ragweed VOCs, soybean and wheat produced significantly less aboveground dry mass, whereas maize did not. Ragweed remained unaffected when exposed to VOCs from the crops or a conspecific. All crops and ragweed significantly avoided root growth toward the root exudates of ragweed. The study shows that the plant response to either above- or belowground chemical cues is highly dependent on the identity of the neighbor, pointing out the complexity of plant-plant communication in plant communities.

Ecological aspects of volatile organic compounds emitted by exotic invasive plants

Exotic invasive plants are present in almost all terrestrial ecosystems. Their spread and ability to colonize new habitats are predicted to increase with human travel, global trade, and climate change. These plants alter the environments they invade in multiple ways, affecting surrounding species. Chemically, invasive plants can modify their environment by releasing secondary metabolites such as root exudates (liquid) or airborne (gaseous) volatile organic compounds (VOCs). The allelopathic effect of invasive species' root exudates is well studied and acknowledged as a trait contributing to invasiveness. However, less is known about the effects of invasive species' VOCs, which are likely to play important ecological roles. Therefore, we conducted a systematic review of the literature during the last decade (2012–2022) to explore what is known about the ecological aspects of VOCs emitted by invasive plants, focusing on the factors affecting their emission (genetic, biotic, and abiotic), and their role on plant-plant and plant-insect interactions. We found 29 studies matching our search criteria. These studies suggest that invasive species are more “chemically diverse” than their native counterparts and have different chemical behavior in native compared to invaded ranges. The studies further highlight that chemical traits are heritable and contribute to invasiveness. Multiple biotic and abiotic factors affecting invasive plants' VOC emission have been explored (e.g., herbivory, soil microorganisms, warming, and CO2). The studies indicate that invasive plants may experience less variation in their VOC emissions in response to environmental change than natives, with trade-offs between growth, reproduction and defense influencing VOC emissions. Regarding the impact on native species and their interactions, the allelopathic role of invasive plants' VOCs on native plants is well documented, consistently showing phytotoxic effects. There is also evidence of their involvement in neighbor detection. While volatile-mediated interactions between invasive plants and native insects remain poorly studied, the existing evidence shows that invasive plant VOCs have the potential to disrupt communication between native plants and insects. But insects also use multiple cues to make foraging/oviposition decisions, compensating for the disruptive effect of invasive plant VOCs. To conclude, we identify knowledge gaps and propose avenues for future research.

Airborne dimethyl sulfide (DMS) cues dimethylsulfoniopropionate (DMSP) increases in the intertidal green alga Ulva fenestrata

Although the use of airborne molecules as infochemicals is common in terrestrial plants, it has not been shown to occur in an ecologically relevant context in marine seaweeds. Like terrestrial plants, intertidal plants spend part of their lives emersed at low tide and release volatile organic compounds (VOCs) into the air when they are grazed or physiologically stressed. We hypothesized seaweeds could use airborne VOCs as infochemicals and respond to them by upregulating a keystone defensive metabolite, dimethylsulfoniopropionate (DMSP). We conducted laboratory and field experiments in which Ulva fenestrata was exposed to airborne dimethyl sulfide (DMS), a volatile antiherbivore and antioxidant metabolite released when the seaweed is grazed or physiologically stressed. In the laboratory, U. fenestrata exposed to DMS had 43–48% higher DMSP concentrations, relative to controls, 6–9 days after exposure. In the field, U. fenestrata 1 m downwind of DMS emitters had 19% higher DMSP concentrations than upwind seaweeds after 11 days. To our knowledge, this is the first demonstration of a marine plant using an airborne molecule released when damaged to elicit defensive responses. Our study suggests that the ability to detect airborne compounds has evolved multiple times or before the divergence of terrestrial plants and green algae.

Gas-phase degradation of VOCs using supported bacteria biofilms.

Herein we report the use of Pseudomonas putida F1 biofilms grown on carbonized cellulosic fibers to achieve biodegradation of airborne volatile organic compounds (VOCs) in the absence of any bulk aqueous-phase media. It is believed that direct exposure of gaseous VOC substrates to biomass may eliminate aqueous-phase mass transfer resistance and facilitate VOC capture and degradation. When tested with toluene vapor as a model VOC, the supported biofilm could grow optimally at 300 p.p.m. toluene and 80% relative humidity, with a specific growth rate of 0.425 day-1 . During long-term VOC biodegradation tests in a tubular packed bed reactor, biofilms achieved a toluene degradation rate of 2.5 mg gDCW -1 h-1 during the initial growth phase. Interestingly, the P. putida F1 film kept biodegrading activity even at the stationary nongrowth phase. The supported biofilms with a biomass loading of 20% (wt) could degrade toluene at a rate of 1.9 mg gDCW -1 h-1 during the stationary phase, releasing CO2 at a rate of 6.4 mg gDCW -1 h-1 at the same time (indicating 100% conversion of substrate carbon to CO2 ). All of these observations promised a new type of "dry" biofilm reactors for efficient degradation of toxic VOCs without involving a large amount of water.

Effects of cleaning spray use on eyes, airways, and ergonomic load

BackgroundCleaning workers are exposed to chemicals and high physical workload, commonly resulting in airway problems and pain. In this study the response in the upper airways and the physical workload following airborne and ergonomic exposure of cleaning spray was investigated.MethodsA survey was answered by professional cleaning workers to investigate their use of cleaning sprays and the perceived effects on eyes, airways and musculoskeletal pain. A human chamber exposure study was then conducted with 11 professional cleaning workers and 8 non-professional cleaning workers to investigate the airborne exposure, acute effects on eyes and airways, and physical load during cleaning with sprays, foam application and microfiber cloths premoistened with water. All cleaning products used were bleach, chlorine, and ammonia free. The medical assessment included eye and airway parameters, inflammatory markers in blood and nasal lavage, as well as technical recordings of the physical workload.ResultsA high frequency of spray use (77%) was found among the 225 professional cleaning workers that answered the survey. Based on the survey, there was an eight times higher risk (p < 0.001) of self-experienced symptoms (including symptoms in the nose, eyes and throat, coughing or difficulty breathing) when they used sprays compared to when they cleaned with other methods. During the chamber study, when switching from spray to foam, the airborne particle and volatile organic compound (VOC) concentrations showed a decrease by 7 and 2.5 times, respectively. For the whole group, the peak nasal inspiratory flow decreased (-10.9 L/min, p = 0.01) during spray use compared to using only water-premoistened microfiber cloths. These effects were lower during foam use (-4.7 L/min, p = 0.19). The technical recordings showed a high physical workload regardless of cleaning with spray or with water.ConclusionSwitching from a spraying to a foaming nozzle decreases the exposure of both airborne particles and VOCs, and thereby reduces eye and airway effects, and does not increase the ergonomic load. If the use of cleaning products tested in this study, i.e. bleach, chlorine, and ammonia free, cannot be avoided, foam application is preferable to spray application to improve the occupational environment.

Proven Impact of an Advanced Air Purification System in the Reduction of Infectious Airborne and Surface Pathogens, Concomitant Reduction of Hospital-acquired Infections and Length of Stay, and Improvement in Health-care Economics.

Proven Impact of an Advanced Air Purification System in the Reduction of Infectious Airborne and Surface Pathogens, Concomitant Reduction of Hospital-acquired Infections and Length of Stay, and Improvement in Health-care Economics.

Explication on distribution patterns of volatile organic compounds in petro-chemistry and oil refineries of China using a species-transport model and health risk assessment

Volatile organic compounds (VOCs) from industrial emissions have attracted great attention due to their negative effects on human, but there is lack of deterministic air quality model for VOC emissions. In this study, airborne VOCs from a typical petrochemical and oil refinery region, Lanzhou, Gansu province of China, were on-site measured. The regional pollution patterns were investigated using a species transport model and the health risks were evaluated. The spatial distribution of VOCs showed that 87.5 % of the airborne VOCs were benzene, toluene, ethylbenzene, and xylene having higher concentration (146 μg/m3) in the north direction oil refinery industrial areas. The concentrations of toluene and benzene were as high as 41.5 and 33.3 μg/m3 in the 4 km2 area away from the petrochemical emission source, respectively, and the concentration of o−/m + p-xylene was up to 79.7 μg/m3. Based on the measured concentration data, the numerical results showed that the accumulation of high concentration of VOC species by mass transfer in the region is related to the atmospheric diffusion driven by downward-moving air over the valley areas. Non-carcinogenic risk assessments showed that airborne benzene exposure had acceptable hazard quotient of 0.185 for adults, which was 1.8 times of children's (0.102), whereas it was found that a high carcinogenic risk (>10−4) from benzene in several sampling sites and diffuse distance become significant for carcinogenic risk. This study verified the effectiveness of VOC atmospheric diffusion model through a large number of on-site monitoring data, providing data support for model-based risk assessment.

Polyurethane Foam Face Masks as a Dosimeter for Quantifying Personal Exposure to Airborne Volatile and Semi-Volatile Organic Compounds.

Airborne volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs) are commonly quantitated by collecting the analytes on solid sorbent tubes or passive air samplers, followed by solvent extraction and instrumental analysis, or by grab bag/canister measurements. We report herein a user-friendly sampling method by breathing through polyurethane foam (PUF) face masks to collect airborne VOCs and SVOCs for chemical analysis. Specifically, dibasic esters, phthalate esters, polycyclic aromatic hydrocarbons, linalool, and nicotine trapped on PUF masks were quantitated by gas chromatography-mass spectrometry analysis as model VOCs and SVOCs. Results showed that the amount of these model VOCs and SVOCs trapped on PUF masks is proportional to the exposure duration. After cross-validation by parallel sampling using XAD-2 packed sorbent tubes, the method was used to quantitate VOCs and SVOCs in a variety of indoor and outdoor environments with varying air concentrations of analytes, temperature, humidity, and wind speed. Because air pollution is considered a major cause of many human diseases and premature deaths and the developed PUF mask sampling method showed high trapping efficiencies for both VOCs and SVOCs, it is believed that the developed sampling method will find wide application in assessing air pollution-associated disease risks with possible extension to more classes of VOCs and SVOCs when coupled with suitable instrumental detection methods.

Characterization of synthetic turf rubber granule infill in Japan: Volatile organic compounds

There has been extensive studies on the composition of tires and industrial rubber. However, there is insufficient information on volatile organic compounds (VOCs) emitted from rubber granule products used to fill synthetic turf fields. In this study, we applied a passive sampling method for assessing the VOCs emitted from rubber granule products used for filling synthetic turf fields. We also performed a quantitative component analysis using a gas chromatography–mass spectrometer (GC–MS). The component analysis results of 46 rubber granule-based products showed the predominant presence of benzothiazole and methyl isobutyl ketone. The level of benzene, which the International Agency for Research on Cancer classifies as a substance with sufficient evidence for carcinogenicity to humans, was below the lower quantification limit in the products tested in this study. Our study included most of the rubber granule products used for synthetic turf fields in Japan (>95% of the products in the current domestic market of Japan). Therefore, we obtained a comprehensive overview of the VOCs emitted from the rubber granule-based products used in Japan's synthetic turf fields. Estimating the exposure to these airborne VOCs is essential to evaluate the adverse health effects of the VOCs emitted from these rubber granule-based products. Our sampling method and results can help provide key data for such risk assessment studies in the future.

Modelling the equilibrium partitioning of low concentrations of airborne volatile organic compounds in human IVF laboratories

Research questionCan volatile organic compounds (VOC) be modelled in an IVF clinical setting? DesignThe study performed equilibrium modelling of low concentrations of airborne VOC partitioning from the air phase into the oil cover layer into the water-based culture media and into/onto the embryo (air–oil–water–embryo). The air-phase VOC were modelled based on reported VOC concentrations found in modern assisted reproductive technology (ART) suites, older IVF clinics, and hospitals, as well as at 10 parts per billion (ppb) and 100 ppb for all compounds. The modelling was performed with 23 documented healthcare-specific VOC. ResultsBased on the partitioning model, seven compounds (acrolein, formaldehyde, phenol, toluene, acetaldehyde, ethanol and isopropanol) should be of great concern to the embryologist and clinician. Acrolein, formaldehyde, phenol, toluene and acetaldehyde are the VOC with the most potent cytotoxic factor and the highest toxic VOC concentration in media. In addition, ethanol and isopropanol are routinely found in the greatest air-phase concentrations and modelled to have the highest water-based culture concentrations. ConclusionsThe results of the equilibrium partitioning modelling of VOC provides a fundamental understanding of how airborne VOC partition from the air phase and negatively influence human IVF outcomes. The results presented here are based on the theoretical model and the values presented have not yet been measured in a laboratory or clinical setting. High air-phase concentrations and toxic concentrations of VOC in culture media are likely indicators of poor clinical outcomes. Based on this model, improved air quality in IVF laboratories reduces the chemical burden imparted on embryos, which supports findings of improved IVF outcomes with reduced air-phase VOC concentrations.

Test of communication between potato plants in response to herbivory by the Colorado potato beetle

Abstract Plant communication via airborne volatile organic compounds is a widespread phenomenon by which volatile organic compounds from damaged plants boost herbivore resistance in receiver plants. This phenomenon has been studied only in a handful of crop species. We tested for communication between potato (Solanum tuberosum) plants in response to herbivory by the Colorado potato beetle, Leptinotarsa decemlineata. For this, we performed a greenhouse experiment with 15 potato varieties for which we caged pairs of plants (i.e., emitters and receivers) of the same variety. Half of the emitter plants were subjected to leaf damage by beetle larvae and the other half remained intact. We collected volatile organic compounds from emitter plants and estimated L. decemlineata damage on receivers. We found no evidence of quantitative (total production) or qualitative (compound composition) changes in volatile organic compound emissions due to beetle herbivory. In addition, the leaf damage treatment on emitters had no significant effect on receiver herbivore resistance, suggesting no communication between infested and non‐infested potato plants in response to Colorado potato beetle damage. Overall, this study provides baseline information on airborne signalling (or the lack of thereof) in potato plants which can inform subsequent work that identifies airborne volatiles with potentially strong effects on priming or defence induction.

Does improving indoor air quality lessen symptoms associated with chemical intolerance?

To determine whether environmental house calls that improved indoor air quality (IAQ) is effective in reducing symptoms of chemical intolerance (CI). Prevalence of CI is increasing worldwide. Those affected typically report symptoms such as headaches, fatigue, 'brain fog', and gastrointestinal problems - common primary care complaints. Substantial evidence suggests that improving IAQ may be helpful in reducing symptoms associated with CI. Primary care clinic patients were invited to participate in a series of structured environmental house calls (EHCs). To qualify, participants were assessed for CI with the Quick Environmental Exposure and Sensitivity Inventory. Those with CI volunteered to allow the EHC team to visit their homes to collect air samples for volatile organic compounds (VOCs). Initial and post-intervention IAQ sampling was analyzed by an independent lab to determine VOC levels (ng/L). The team discussed indoor air exposures, their health effects, and provided guidance for reducing exposures. Homes where recommendations were followed showed the greatest improvements in IAQ. The improvements were based upon decreased airborne VOCs associated with reduced use of cleaning chemicals, personal care products, and fragrances, and reduction in the index patients' symptoms. Symptom improvement generally was not reported among those whose homes showed no VOC improvement. Improvements in both IAQ and patients' symptoms occur when families implement an action plan developed and shared with them by a trained EHC team. Indoor air problems simply are not part of most doctors' differential diagnoses, despite relatively high prevalence rates of CI in primary care clinics. Our three-question screening questionnaire - the BREESI - can help physicians identify which patients should complete the QEESI. After identifying patients with CI, the practitioner can help by counseling them regarding their home exposures to VOCs. The future of clinical medicine could include environmental house calls as standard of practice for susceptible patients.

The Positive Impact of a Novel Air Purification Technology on Environmental and Clinical Outcomes

Reducing sources of illness improves resident care. An advanced air purification technology (AAPT) was designed to destroy the DNA and RNA of all bacteria, fungi and viruses, rendering them non-infectious and to remediate volatile organic compounds (VOCs). This study compares the biological, fungal and VOC loading using the AAPT to standard high efficiency particulate air (HEPA) filtration. It was hypothesized that the AAPT would be associated with reductions in airborne and surface pathogens, VOCs and improved clinical metrics. A control floor with HEPA filtration and study floor with AAPT remediation were studied. Measurements of total VOCs and airborne and surface bacteria and fungi were measured in five locations on each floor. The facility acquired infection (FAI) rate, the number of infections divided by total patient days, showed a 57% difference between the control floor (2.33 FAIs/month) and the study floor (1.00 FAIs/month) and a decrease of 39.75% pre-installation (1.66 FAIs/month) to post-installation (1.00 FAIs/month). The viable pathogen loading measured on the study floor was reduced from an average of 483.8 colony forming units (CFU)/m3 pre-installation to an average of 56 CFU/m3 post-installation. VOCs were reduced from an average of 641.66 parts per billion (PPB) to 64.96 PPB and viable surface bacteria from an average of 110.6 CFU/m3 to 97.2 CFU/m3. The AAPT significantly reduced levels of infectious airborne and surface pathogens and VOC levels. As a result, residents on the AAPT floor demonstrated significant improvements in FAI rates. The findings support the hypothesis that environmental factors impact resident wellness.

Quantitative volatile organic compound sensing with liquid crystal core fibers

SummaryPolymer fibers with liquid crystals (LCs) in the core have potential as autonomous sensors of airborne volatile organic compounds (VOCs), with a high surface-to-volume ratio enabling fast and sensitive response and an attractive non-woven textile form factor. We demonstrate their ability to continuously and quantitatively measure the concentration of toluene, cyclohexane, and isopropanol as representative VOCs, via the impact of each VOC on the LC birefringence. The response is fully reversible and repeatable over several cycles, the response time can be as low as seconds, and high sensitivity is achieved when the operating temperature is near the LC-isotropic transition temperature. We propose that a broad operating temperature range can be realized by combining fibers with different LC mixtures, yielding autonomous VOC sensors suitable for integration in apparel or in furniture that can compete with existing consumer-grade electronic VOC sensors in terms of sensitivity and response speed.

The feasibility and temporal storability of gas phase standards of volatile organic compounds prepared through liquid phase vaporization in polyester aluminum bags at room temperature

Currently, the presence of many classes of volatile organic compounds (VOCs) in indoor air is well recognized. There is an impetus to accurately quantify airborne VOCs for the proper assessment of their human health risks. VOC standards prepared in a solvent are often vaporized in N2 gas-filled sampling bags for external calibration as the use of grab sampling bags is a common practice for the collection of real ambient air samples. Such practices can nontheless be subject to many sources of biases in their calibration (e.g., VOC chemical reaction with the solvent, adsorption on the bag interior surface, or leakage). The main goal of this work is to measure the temporal stability of 11 VOC targets (benzene, toluene, o-xylene, styrene, propionaldehyde, n-butyraldehyde, isovaleraldehyde, valeraldehyde, acrylonitrile, isoprene, and methyl ethyl ketone) selected in this research over 24 h which started 10 min after the injection and vaporization of liquid-phase standards (all prepared in methanol solvent) into polyester aluminum (PEA) bags containing 1 atm N2. Although all tested VOCs showed gradual decreases of their concentrations (e.g., >17% in 24 h), the aromatic hydrocarbon VOCs (namely BTXS) yielded the best relative recoveries (e.g., decreases of 11%–30% in 24 h) and relative errors (e.g., relative standard error (RSE) = 2.14–3.59%) in 5 replicate tests. A good linear relationship was established between the 24 h VOC relative recovery and molecular weight (R2 > 0.81). The results of this study offers valuable clues to properly reduce the bias in the calibration of gas-phase VOC standards when calibrating the system through the vaporization of liquid-phase VOC standards prepared in a solvent.

Deepwater Horizon 2010: Subsea dispersants protected responders from VOC exposure

Controversy remains on the use of Sub-Sea Dispersant Injection (SSDI) during the Deepwater Horizon (DWH) spill to minimize the exposure of responders on surface vessels to volatile organic compounds (VOC). Here, we use extensive evidence (>90,000 VOC measurements) collected near the oil well MC252 site during the DWH spill and demonstrate at a high level of statistical confidence that SSDI enhanced the safety and health conditions of the responders at the water surface through the reduction of airborne VOC concentrations in a dose-dependent manner. VOC levels on ships' decks were clearly diminished (p < 0.001) during subsea dispersant use, and incidents of peak concentrations (>50 ppm VOC) that could have been an immediate concern to worker health were reduced by a factor of ~6 to 19 when dispersants were delivered at the intended rate. SSDI thus played an important role in minimizing potential exposure to VOC, and should be embedded in guidelines and regulations for dispersant use.

Airborne volatile organic compounds at an e-waste site in Ghana: Source apportionment, exposure and health risks

Informal e-waste recycling processes emit various air pollutants. While there are a number of pollutants of concern, little information exists on volatile organic compounds (VOCs) releases at e-waste sites. To assess occupational exposures and estimate health risks, we measured VOC levels at the Agbogbloshie e-waste site in Ghana, the largest e-waste site in Africa, by collecting both fixed-site and personal samples for analyzing a wide range of VOCs. A total of 54 VOCs were detected, dominated by aliphatic and aromatic compounds. Mean and median concentrations of the total target VOCs were 46 and 37 μg/m3 at the fixed sites, and 485 and 162 μg/m3 for the personal samples. Mean and median hazard ratios were 2.1 and 1.4, respectively, and cancer risks were 4.6 × 10-4 and 1.5 × 10-4. These risks were predominantly driven by naphthalene and benzene; chloroform and formaldehyde were also high in some samples. Based on the VOC composition, the major sources were industry, fuel evaporation and combustion. The concentration gradient across sites and the similarity of VOC profiles indicated that the e-waste site emissions reached neighboring communities. Our results suggest the need to protect e-waste workers from VOC exposure, and to limit emissions that can expose nearby populations.