From Engineered Stone Slab to Silicosis: A Synthesis of Exposure Science and Medical Evidence.

Engineered stone (ES) is a popular building product, due to its architectural versatility and generally lower cost. However, the fabrication of organic resin-based ES kitchen benchtops from slabs has been associated with alarming rates of silicosis among workers. In 2024, fifteen years after the first reported ES-related cases in the world, Australia became the first country to ban the use and importation of ES. A range of interacting factors are relevant for ES-associated silicosis, including ES material composition, characteristics of dust exposure and lung cell-particle response. In turn, these are influenced by consumer demand, work practices, particle size and chemistry, dust control measures, industry regulation and worker-related characteristics. This literature review provides an evidence synthesis using a narrative approach, with the themes of product, exposure and host. Exposure pathways and pathogenesis are explored. Apart from crystalline silica content, consideration is given to non-siliceous ES components such as resins and metals that may modify chemical interactions and disease risk. Preventive effort can be aligned with each theme and associated evidence.

The aryl hydrocarbon receptor pathway is a marker of lung cell activation but does not play a central pathologic role in engineered stone-associated silicosis.

Engineered stone-associated silicosis is characterised by a rapid progression of fibrosis linked to a shorter duration of exposure. To date, there is lack of information about molecular pathways that regulates disease development and the aggressiveness of this form of silicosis. Therefore, we compared transcriptome responses to different engineered stone samples and standard silica. We then identified and further tested a stone dust specific pathway (aryl hydrocarbon receptor [AhR]) in relation to mitigation of adverse lung cell responses. Cells (epithelial cells, A549; macrophages, THP-1) were exposed to two different benchtop stone samples, standard silica and vehicle control, followed by RNA sequencing analysis. Bioinformatics analyses were conducted, and the expression of dysregulated AhR pathway genes resulting from engineered stone exposure was then correlated with cytokine responses. Finally, we inhibited AhR pathway in cells pretreated with AhR antagonist and observed how this impacted cell cytotoxicity and inflammation. Through transcriptome analysis, we identified the AhR pathway genes (CYP1A1, CYP1B1 and TIPARP) that showed differential expression that was unique to engineered stones and common between both cell types. The expression of these genes was positively correlated with interleukin-8 production in A549 and THP-1 cells. However, we only observed a mild effect of AhR pathway inhibition on engineered stone dust induced cytokine responses. Given the dual roles of AhR pathway in physiological and pathological processes, our data showed that expression of AhR target genes could be markers for assessing toxicity of engineered stones; however, AhR pathway might not play a significant pathologic role in engineered stone-associated silicosis.

Understanding the pathogenesis of engineered stone-associated silicosis: The effect of particle chemistry on the lung cell response.

BACKGROUND AND OBJECTIVE: The resurgence of severe and progressive silicosis among engineered stone benchtop industry workers is a global health crisis. We investigated the link between the physico-chemical characteristics of engineered stone dust and lung cell responses to understand components that pose the greatest risk. METHODS: Respirable dust from 50 resin-based engineered stones, 3 natural stones and 2 non-resin-based materials was generated and analysed for mineralogy, morphology, metals, resin, particle size and charge. Human alveolar epithelial cells and macrophages were exposed in vitro to dust and assessed for cytotoxicity and inflammation. Principal component analysis and stepwise linear regression were used to explore the relationship between engineered stone components and the cellular response. RESULTS: Cutting engineered stone generated fine particles of <600 nm. Crystalline silica was the main component with metal elements such as Ti, Cu, Co and Fe also present. There was some evidence to suggest differences in cytotoxicity (p = 0.061) and IL-6 (p = 0.084) between dust samples. However, IL-8 (CXCL8) and TNF-α levels in macrophages were clearly variable (p < 0.05). Quartz explained 11% of the variance (p = 0.019) in macrophage inflammation while Co and Al accounted for 32% of the variance (p < 0.001) in macrophage toxicity, suggesting that crystalline silica only partly explains the cell response. Two of the reduced-silica, non-engineered stone products induced considerable inflammation in macrophages. CONCLUSION: These data suggest that silica is not the only component of concern in these products, highlighting the caution required as alternative materials are produced in an effort to reduce disease risk.

Assessing the Usefulness of Mobile Apps for Noise Management in Occupational Health and Safety: Quantitative Measurement and Expert Elicitation Study.

Background: Overexposure to occupational noise can lead to hearing loss. Occupational noise mapping is conventionally performed with a calibrated sound level meter (SLM). With the rise of mobile apps, there is a growing number of SLM apps available on mobile phones. However, few studies have evaluated such apps for accuracy and usefulness to guide those with occupational noise detection needs in selecting a quality app. Objective: The purpose of this study was to evaluate the accuracy and usefulness of SLM mobile apps to guide workplace health and safety professionals in determining these apps' suitability for assessing occupational noise exposure. Methods: The following three iOS apps were assessed: the NIOSH (National Institute for Occupational Safety and Health) Sound Level Meter, Decibel X, and SoundMeter X apps. The selected apps were evaluated for their accuracy in measuring sound levels in low-, moderate-, and high-noise settings within both simulated environments and real-world environments by comparing them to a conventional SLM. The usefulness of the apps was then assessed by occupational health specialists using the Mobile App Rating Scale (MARS). Results: The NIOSH Sound Level Meter app accurately measured noise across a range of sound levels in both simulated settings and real-world settings. However, considerable variation was observed between readings. In comparison, the Decibel X and SoundMeter X apps showed more consistent readings but consistently underestimated noise levels, suggesting that they may pose a risk for workers. Nevertheless, none of the differences in sound measurements between the three apps and the conventional SLM were statistically significant (NIOSH Sound Level Meter: P=.78; Decibel X: P=.38; SoundMeter X: P=.40). The MARS scores for the three apps were all above 3.0, indicating the usefulness of these apps. Conclusions: Under the conditions of this study, the NIOSH Sound Level Meter app had equivalent accuracy to the calibrated SLM and a degree of usefulness according to the MARS. This suggests that the NIOSH Sound Level Meter app may be suitable for mapping noise levels as part of a monitoring strategy in workplaces. However, it is important to understand its limitations. Mobile apps should complement but not replace conventional SLMs when trying to assess occupational noise exposure risk. Our outcomes also suggest that the MARS tool may have limited applicability to measurement-based apps and may be more suited to information-based apps that collect, record, and store information.

Temporal decline in serum PFAS concentrations among metropolitan firefighters: Longitudinal study on post-exposure changes following PFAS foam cessation.

Firefighters are at a high risk of exposure to per- and polyfluoroalkyl substances (PFAS) due to their frequent use of PFAS-containing foams in training and emergency situations. This longitudinal study aimed to investigate the changes in serum PFAS levels among firefighters following cessation of their exposure to PFAS-containing foams. The study involved 130 firefighters from the South Australian Metropolitan Fire Services (SAMFS), and serum samples were collected at two time points: baseline in 2018-19 and follow-up in 2021-22. Along with the collection of samples, a survey questionnaire was administered to gather information on firefighters' employment and demographic characteristics. Regression models were employed to assess the association between these factors and the outcome variable (annual percentage change in serum PFAS concentration). The results indicated a decline in serum PFAS concentrations over time, with the main contaminants being perfluorooctane sulfonic acid (PFOS), perfluorohexane sulfonate (PFHxS), and perfluorooctanoic acid (PFOA). The median and Interquartile Range (IQR) of total PFAS (∑PFAS) concentration reduced from 21.5 ng/ml (IQR: 11 to 53 ng/ml) at baseline to 15 ng/ml (IQR: 8 to 33 ng/ml) at follow-up. On average, there was an annual reduction of 13%, 7%, and 4.4% in serum concentrations of PFOS, PFHxS, and PFOA, respectively. Firefighters under the age of 55, those who used PFAS in the past ten years, or those who had little to no frequency of PFAS exposure in their previous employment, encountered a significantly higher annual percentage reduction (P < 0.05) in both ∑PFAS and PFOS concentrations. None of the independent variables analysed could significantly predict the annual percentage change in PFOA and PFHxS. This study provides evidence for a declining temporal trend in serum PFAS concentrations among metropolitan firefighters following workplace interventions that involved the removal of PFAS-containing foams.

An approach to quantify ortho-phthalaldehyde contamination on work surfaces.

Ortho-phthalaldehyde (OPA) is used as a high-level disinfectant for reusable medical devices in healthcare settings. The ACGIH recently adopted a Threshold Limit Value-Surface Limit (TLV-SL; 25 µg/100 cm2) for OPA surface contamination to prevent induction of dermal and respiratory sensitization following dermal exposure. However, there is no current validated method to measure OPA surface contamination. This study aimed to develop a standardized approach for sample collection and quantitative determination of OPA from work surfaces for use in risk assessment practices. The reported method utilises readily available commercial wipes to collect surface samples coupled with direct detection of OPA via liquid chromatography time of flight mass spectrometry (LC-ToF-MS). This approach avoided complex derivatization steps commonly required for the analysis of aldehydes. Method evaluation was conducted in accordance with the Occupational Safety and Health Administration (OSHA) surface sampling guidelines. Overall recoveries of 25 µg/100 cm2 of OPA from stainless steel and glass surfaces were 70% and 72%, respectively. The reported LOD for this method was 1.1 µg/sample and the LOQ was 3.7 µg/sample. OPA remained stable on the sampling medium for up to 10 days, when stored at 4 °C. The method was demonstrated in a workplace surface assessment at a local hospital sterilising unit, successfully detecting OPA on work surfaces. This method is intended to supplement airborne exposure assessment and provide a quantitative assessment tool for potential dermal exposure. When used in conjunction with a thorough occupational hygiene program that includes hazard communication, engineering controls, and personal protective equipment, skin exposure and consequent sensitization risks in the workplace can be minimized.

Engineered Stone Fabrication Work Releases Volatile Organic Compounds Classified as Lung Irritants.

Engineered stones are often characterized for their crystalline silica content. Their organic composition, particularly that of the emissions generated during fabrication work using hand-held power tools, is relatively unexplored. We forensically screened the emissions from dry-cutting 12 engineered stone products in a test chamber for their organic composition by pyrolysis-gas chromatography-mass spectrometry (GC-MS) plus selected traditional capture and analysis techniques. Phthalic anhydride, which has a Respiratory Sensitization (RSEN) Notation by the American Conference of Governmental Industrial Hygienists (ACGIH), was the most common and abundant compound, at 26-85% of the total organic composition of engineered stone emissions. Benzaldehyde and styrene were also present in all twelve samples. During active cutting, the predominant volatile organic compound (VOC) emitted was styrene, with phthalic anhydride, benzene, ethylbenzene, and toluene also detected. These results have important health implications as styrene and phthalic anhydride are irritants to the respiratory tract. This study suggests a risk of concurrent exposure to high levels of respirable crystalline silica and organic lung irritants during engineered stone fabrication work.

Food grown on fire stations as a potential pathway for firefighters' exposure to per- and poly-fluoroalkyl substances (PFAS).

Human exposure to per- and polyfluoroalkyl substances also known as PFAS is an ongoing occupational and environmental health problem. This study seeks to characterise multiple pathways for firefighters' exposure to PFAS. PFAS were analysed in 688 environmental samples such as eggs, fruits, vegetables, dust, soil, surface swabs, appliance washes and water obtained from fire stations. Relevant exposure pathways were identified and daily intake levels were estimated using PFAS concentrations and exposure factors relevant to firefighters. Five PFAS including perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorohexane sulfonic acid (PFHxS), 6:2 fluorotelomer sulfonate (6:2 FTS), and 8:2 fluorotelomer sulfonic acid (8:2 FTS) were frequently detected in the samples. Based on the median concentrations in each sample type, PFOS was the most abundant contaminant in eggs (80%), fruits (52%), dust (81%), surface swab (66%), soil (83%) and appliance wash (31%) samples. On the other hand, PFHxS was most abundant in vegetables (77%) and 8:2 FTS in water (58%). The intake estimation results show that dietary exposure from ingestion of foods produced on fire stations was the predominant exposure pathway, representing 82% and 62% of firefighters' total PFAS intake under typical and worst-case exposure scenarios, respectively. Incidental ingestion and dermal absorption of PFAS in dust contributed 15% for typical and 34% for worst-case exposure scenarios. The relative contributions from incidental ingestion and dermal absorption of PFAS in soil and appliance washes were insignificant. Overall, the study identifies multiple exposure pathways relevant to career firefighters including consumption of food grown on fire stations, which has not previously been recognised within the occupational exposure context. The results suggest exposure control strategies that target foods produced on fire stations could substantially reduce firefighters' exposure to PFAS.

In vitro assessment of the dermal penetration potential of sodium fluoroacetate using a formulated product.

This paper presents experimental data on the skin absorption of sodium fluoroacetate from a formulated product using an in vitro approach and human skin. Sodium fluoroacetate is a pesticide, typically applied in formulation (1080) for the control of unwanted vertebrate invasive species. It has been assigned a Skin Notation by the ACGIH, and other international workplace health regulatory bodies, due to its predicted ability to permeate intact and abraded human skin. However, there is a distinct lack of experimental data on the skin absorption of sodium fluoroacetate to support this assignment. This study found that sodium fluoroacetate, as a formulated product, permeated the human epidermis when in direct contact for greater than 10 hr. A steady-state flux (Jss) of 1.31 ± 0.043 µg/cm2/hr and a lag time of 6.1 hr was calculated from cumulative skin permeation data. This study provides important empirical evidence in support of the assignment of a Skin Notation.

Rapid Assessment of Oxidative Damage Potential: A Comparative Study of Engineered Stone Dusts Using a Deoxyguanosine Assay.

The popularity of engineered stone (ES) has been associated with a global increase in occupational lung disease in workers exposed to respirable dust during the fabrication of benchtops and other ES products. In this study, the reactivity and subsequent oxidative reduction potential of freshly generated ES dusts were evaluated by (i) comparing different engineered and natural stones, (ii) comparing settled and respirable stone dust fractions and (iii) assessing the effect of ageing on the reactivity of freshly generated stone dust. An established cell-free deoxyguanosine hydroxylation assay was used to assess the potential for oxidative DNA damage. ES dust exhibited a higher relative reactivity than two of the three natural stones tested. Respirable dust fractions were found to be significantly more reactive than their corresponding settled fraction (ANOVA, p < 0.05) across all stone types and samples. However, settled dust still displayed high relative reactivity. The lower reactivity of the settled dust was not due to decay in reactivity of the respirable dust when it settled but rather a result of the admixture of larger nonrespirable particles. No significant change in respirable dust reactivity was observed for three ES samples over a 21-day time period, whereas a significant decrease in reactivity was observed in the natural stone studied. This study has practical implications for dust control and housekeeping in industry, risk assessment and hazard management.

What Do Safety Data Sheets for Artificial Stone Products Tell Us About Composition? A Comparative Analysis with Physicochemical Data.

Artificial stone (AS) is a composite material that has seen widespread use in construction, particularly for kitchen benchtops. However, fabrication processes with AS have been associated with serious lung disease. Safety data sheets (SDSs) aim to provide important information pertaining to composition and health risks. In the case of a complex mixture, SDSs may be problematic in terms of specific information on overall health risks. To assess this issue, we compared empirically determined mineral, metallic, and organic resin content of 25 individual AS products across six suppliers, with the corresponding SDS information. X-ray diffraction was used to quantitate the mineralogical components of AS samples, and X-ray fluorescence was used to estimate the metallic components. Organic material (resin content) was estimated using weight loss during calcination. Although the resin content for all AS samples was within the SDS-reported ranges, there was considerable variability in the crystalline silica content when comparing with supplier's SDS. Potentially toxicologically relevant metallic and mineral constituents were not reported. Some supplier SDSs were found to provide more information than others. Only one of the six suppliers provided crystalline mineral content other than silica, and only two suppliers provided any information about metals. There remains a limited understanding of lung pathogenesis from AS, and this study highlights the need for more comprehensive and standardized SDS information for risk assessment and management.

Characterisation of dust emissions from machined engineered stones to understand the hazard for accelerated silicosis.

Engineered stones are novel construction materials associated with a recent upsurge in silicosis cases among workers in the stonemason industry. In order to understand the hazard for the short latency of lung disease among stonemasons, we simulated real-time dust exposure scenario by dry-machining engineered stones in controlled conditions, capturing and analysing the respirable dust generated for physical and chemical characteristics. Natural granite and marble were included for comparison. Cutting engineered stones generated high concentrations of very fine particles (< 1 µm) with > 80% respirable crystalline silica content, in the form of quartz and cristobalite. Engineered stones also contained 8-20% resin and 1-8% by weight metal elements. In comparison, natural stones had far lower respirable crystalline silica (4- 30%) and much higher metal content, 29-37%. Natural stone dust emissions also had a smaller surface area than engineered stone, as well as lower surface charge. This study highlighted the physical and chemical variability within engineered stone types as well as between engineered and natural stones. This information will ultimately help understand the unique hazard posed by engineered stone fabrication work and help guide the development of specific engineering control measures targeting lower exposure to respirable crystalline silica.

Blue light exposure in the workplace: a case study of nail salons.

Fluorescent or LED nail lamps are used in manicure and pedicure salons to cure nail coatings. These are UV sources, but with significant blue light emissions. Most of the literature emphasizes skin damage and cancer risk from UV exposure rather than blue light-induced damage to visual photoreceptors. Nail technicians using the lamps routinely may have potentially greater exposure than customers. However, there are no data on blue light radiance levels combined with time activity patterns for exposure assessment. This research aimed to determine exposures through simulation experiments, informed by observational studies in seven nail salons. Typical and worst-case time activity patterns were established, and spectral radiance doses determined in the occupational visual field for two LED nail curing lamps. The results showed the effective spectral radiance dose were below the current guideline promulgated by the International Commission on Non-Ionising Radiation Protection. Interestingly, radiances at the corners of one LED nail curing lamp was higher than at the center, which shows the amount of exposure can differ depending on the viewing angle. This research is the first to determine spectral radiance doses. A covered design is highly recommended for blocking the emission of blue light from a nail lamp.

The role of formulation co-ingredients in skin and glove barrier protection against organophosphate insecticides.

BACKGROUND: Commercially formulated pesticide products are complex mixtures of one or more active ingredients and several co-ingredients. However, the modifying effect of co-ingredients on skin uptake and glove barrier protection has been poorly studied. The aim of this study was to understand the role of formulation co-ingredients in skin and glove barrier protection performance against organophosphate insecticides. RESULTS: We adapted standard in vitro diffusion cell methods to test permeation kinetics of two commonly used organophosphate insecticides: dimethoate and omethoate. For spray dilutions, dimethoate and omethoate did not reach breakthrough glove permeation rate (1 µg·cm-2 ·min-1 ) and no or little skin permeation was observed for up to 8 h, regardless of formulation. For exposure conditions involving highly concentrated products, significant differences in glove permeation were observed between different formulations of dimethoate (about 1.5-fold, P < 0.05) and of omethoate (184-fold, P < 0.001). In contrast, no difference (P > 0.05) was observed between formulations in terms of skin permeation. CONCLUSION: These results suggest that co-ingredients play a critical role in glove barrier protection against undiluted organophosphate insecticides, whereas their influence on skin uptake was insignificant within the exposure time tested. This implies that dermal exposure risk may vary between handling different formulated products of the same active ingredient hence recommending a common glove material for different formulations of the same chemical without careful consideration of co-ingredients and their permeation properties may not necessarily be appropriate. © 2021 Society of Chemical Industry.

Metal Ion Release from Engineered Stone Dust in Artificial Lysosomal Fluid-Variation with Time and Stone Type.

Inhalational exposure to dust from engineered stone (ES), also known as artificial or composite stone, is associated with a specific disease profile, namely accelerated silicosis, and scleroderma. The pathogenic mechanisms are poorly understood, particularly the role of resin and metal ions. Metal ions are present in pigments and constituent minerals and may be considered potential contributors to toxicity. The aim of this preliminary study was to understand the solubility of ES-containing metals in artificial lysosomal fluid (ALF) simulating the acidic intracellular environment of the lung macrophage lysosome. Differences with respect to ES types and temporal release were explored. Ten ES products of variable colour and company origin were comminuted and assessed for four different metals, solubilized into ALF solutions at 1,2,4 and 8 weeks at 37 °C. There was significant variability in metal release, particularly with regard to iron and manganese, which could be correlated with the reflected brightness of the stone. A majority of the available Mn, Fe, Al and Ti was solubilized. Time trends for metal release varied with ES type but also with metal ion. The data suggest a high metal ion bioavailability once engulfed by lung macrophages. There is a need to investigate a wider range of ES dust and relate metal content to markers of ES toxicity.

What Do Occupational Hygienists Really Know About Skin Exposure?

This article describes responses to a questionnaire on current work practices and understanding of the management of dermal exposure issues in the workplace from members of the British Occupational Hygiene Society (BOHS) and the Australian Institute of Occupational Hygienists (AIOH). The survey comprised questions in four key areas: employment demographics, experience managing dermal exposure, knowledge of dermal exposure management, and opinions on professional knowledge gaps and preferred training methods. The survey was disseminated in 2016 in the UK and 2018 in Australia, with 116 and 114 responses from each jurisdiction, respectively. The majority of respondents had personally evaluated the risks of dermal exposure to chemicals (BOHS 92%; AIOH 86%), albeit infrequently (less than a few times per year). Occupational Hygienists reportedly adopted a range of strategies to control dermal exposure problems, including chemical elimination/substitution (BOHS 68%; AIOH 68%), changing work practices (BOHS 79%; AIOH 75%), and education (BOHS 77%; AIOH 83%). The use of gloves or other personal protective equipment remained the most commonly cited exposure control measure (BOHS 99%; AIOH 97%). While there appeared to be a good understanding of common dermal exposure workplace scenarios (e.g. isocyanate exposure in motor vehicle repair, solvent exposure during spray painting), the overwhelming majority of respondents wished to find out more about assessing the risks from dermal exposure to chemicals (BOHS 89%; AIOH 88%). The outcomes suggest ways to increase the competence of professionals in dealing with dermal exposure matters in the workplace, through mechanisms such as web-based guidance, interactive educational materials and webinars, as well as workshops and seminars.

Glove performance in a warming climate: The role of glove material and climate on permeation resistance to organophosphate insecticides.

Hands and forearms are the principal sites of dermal exposure to organophosphate insecticides, which makes glove use one of the most important components of an exposure control strategy. However, the selection of suitable gloves depends on issues such as task, type, and concentration of organophosphate as well as cost. In addition, chemical protection performance of gloves may be temperature dependent, which is of increasing concern in a warming climate. Two recommended reusable glove materials (polyvinylchloride and nitrile butadiene rubber) and one single-use glove (nitrile/neoprene) were tested for permeation resistance to actual formulations of organophosphate insecticides with active ingredients dimethoate and malathion. Chemical resistance parameters were measured using American society for testing and materials permeation test cells and compared across glove, organophosphate type, and temperature. The three gloves demonstrated comparable and adequate chemical resistance (less than one µg cm-2 min-1 for up to 8 hr exposure; 25-60 °C) for dilute forms of dimethoate and malathion, used during spraying activities. However, the single-use nitrile/neoprene glove is not designed to fully cover the elbow which limits its suitability. In permeation tests that reflect "worst case" exposure scenario to concentrated (neat) organophosphate formulations, as in mixing/loading tasks, a significant variation in chemical resistance between gloves was observed. While polyvinylchloride offered the maximum resistance, physical degradation of nitrile butadiene rubber after 3 hr of continuous exposure makes it unsuitable for handling neat dimethoate. The single-use nitrile/neoprene glove material had considerably poorer permeation resistance (up to 155-fold greater permeation and 6-fold shorter breakthrough) against neat formulations. Overall, elevated temperature (>40 °C) was shown to result in significantly greater (P < 0.05) cumulative permeation of neat formulation insecticides. This work demonstrates the variation in glove performance and potential for greater exposure risk particularly when mixing concentrated pesticides at elevated temperature conditions such as an occluded human skin or hot greenhouses. Training and guidance on testing, selection, use, and storage of gloves should consider in-use exposure scenarios and temperature-induced reduction in chemical protective performance.

Hazardous materials emergency incidents: public health considerations and implications.

OBJECTIVE: Hazardous materials (HAZMAT) incidents, including the deliberate release of toxic chemicals, can cause a significant drain on resources as well as heightened anxiety in the community. Recent high-profile incidents, including the 2018 illegal waste storage fire in Victoria, Australia, have highlighted the complexity but also the value of multidisciplinary approaches to HAZMAT events. This brief report examines issues from a public health perspective and reflects on the experience of such events in South Australia. METHODS: The type, location and time of HAZMAT incidents for the period 2001 to 2018 (inclusive) in South Australia were compiled and classified from a database of the state Technical Advice Coordinator. RESULTS: The profile of HAZMAT events was diverse, including fires, spills, unknown chemicals, sabotage and suicides. Incidents frequently occurred around transportation corridors and storage facilities. Public health agency involvement was most evident for known or suspected biological agents (toxins) and chemical toxicants with persistent exposures. Conclusion and implications for public health: Public health agencies are likely to have a greater future role in HAZMAT management as the complexity of incidents increases (e.g. mass casualty events and events involving vulnerable subpopulations). There is a need for a national HAZMAT surveillance database to coordinate agency responses on a national level. A unified approach to risk communication for vulnerable communities is also critical.

Understanding skin absorption of common aldehyde vapours from exposure during hazardous material incidents.

The toxic release of aldehyde vapours during a hazardous material (HAZMAT) incident primarily results in respiratory concerns for the unprotected public. However, skin absorption may be an important concurrent exposure route that is poorly understood for this scenario. This study provides experimental data on the skin absorption properties of common aldehydes used in industry, including acetaldehyde, acrolein, benzaldehyde and formaldehyde, in gaseous or vapour form using an adapted in vitro technique. Two of the four tested aldehydes were found to penetrate the skin in appreciable amounts following 30-min exposure at HAZMAT relevant atmospheric concentrations: acetaldehyde (5.29 ± 3.24 µg/cm2) and formaldehyde (3.45 ± 2.58 µg/cm2). Whereas only low levels of acrolein (0.480 ± 0.417 µg/cm2) and benzaldehyde (1.46 ± 0.393 µg/cm2) skin penetration was noted. The aldehydes demonstrated differing levels of interaction with fabric. Formaldehyde and acetaldehyde adsorbed strongly to denim, whereas benzaldehyde and acrolein displayed no sink properties. However, denim was shown to be an initial protective barrier and reduced penetration outcomes for all aldehydes. This study provides important information to assist first responders and confirms the relevance of using physicochemical properties (e.g. solubility, molecular weight, partition coefficient) to predict skin permeation potential in the absence of empirical data during HAZMAT incidents involving different types of aldehydes.

Is the skin an important exposure route for workers during cyanogen fumigation?

BACKGROUND: Cyanogen is a toxic flammable gas used as a fumigant in numerous industries. Occupational exposure to cyanogen can occur during its production and use. The most serious human health risk from exposure to cyanogen is via the respiratory system. However, there is also potential for skin exposure in many workplace situations. The extent of skin absorption under occupational exposure scenarios has not been directly assessed. Understanding skin uptake potential may inform risk assessment and exposure control measures. RESULTS: We describe an in vitro experimental system using human epidermis and dynamic atmosphere exposure to cyanogen to mimic potential workplace exposures. The influence of clothing and ventilation on skin permeation outcomes were also assessed. No evidence of transdermal permeation was found at 100 or 1000 ppm exposures, while permeation of 0.99 ± 0.38 µg cm-2 was observed after 60 min exposure to 10 000 ppm. Fabric on skin and skin ventilation had no additional influence on transdermal permeation compared with naked skin, but fabric provided a reservoir for potential secondary exposures. CONCLUSION: Results show dermal uptake following cyanogen exposure is possible, but only at very high atmospheric concentrations (10 000 ppm after >15 min exposure). Importantly, this could have implications for fumigant applicators who may only be wearing personal respiratory protection. These empirical data may be used in conjunction with other relevant toxicological information in determining whether a Skin Notation is warranted for Workplace Exposure Standard setting. © 2019 Society of Chemical Industry.