A Case Study of Brass Foundry Workers’ Estimated Lead (Pb) Body Burden from Different Exposure Routes

Objectives The most pronounced occupational exposure routes for lead (Pb) are inhalation and gastrointestinal uptake mainly through hand-to-mouth behaviour. Skin absorption has been demonstrated for organic Pb compounds, but less is known about inorganic Pb species. Several legislative bodies in Europe are currently proposing lowering biological exposure limit values and air exposure limits due to new evidence on cardiovascular effects at very low blood Pb levels. In light of this, all exposure routes in occupational settings should be revisited to evaluate how to lower the overall exposure to Pb. Methods The aim of the study was to investigate the possible exposure routes in workers operating computer numerical control-machines in a brass foundry and specifically to understand if metal cutting fluids (MCFs) used by the workers could lead to skin absorption of Pb. The different bronze alloys at the facility may contain up to 20% Pb. After obtaining written informed consent from the workers (n = 7), blood, skin wipes, and personal air samples were collected. In addition, MCFs used on the day of exposure measurements were collected for in vitro skin absorption studies using stillborn piglet skin mounted in static Franz diffusion cells (n = 48). All samples were analysed for Pb content using inductively coupled plasma mass spectrometry. Results Pb air concentration (<0.1–3.4 µg m−3) was well below the Swedish occupational exposure limit value. Blood Pb was in the range of <0.72–33 µg dl−1, and Pb on skin surfaces, after performing normal work tasks during 2 h, was in the range of 0.2–48 µg cm−2. Using the MCFs in diffusion cells showed that skin absorption had occurred at very low doses, and that up to 10% of the Pb content was present in the skin after 24 h exposure. Using these results in the US EPA adult lead model, we could estimate a contribution to blood Pb from the three exposure routes; where hand-to-mouth behaviour yielded the highest contribution (16 µg Pb dl−1 blood), followed by skin absorption (3.3–6.3 µg Pb dl−1 blood) and inhalation (2.0 µg Pb dl−1 blood). Conclusions This case study shows that MCF may lead to skin absorption of inorganic Pb and contribute to a systemic dose (quasi-steady state). Furthermore, even though good hand hygienic measures were in place, the workers’ skin exposure to Pb is in all likelihood an important contributor in elevating blood Pb levels. Skin exposure should thus be monitored routinely in workers at facilities handling Pb, to help reducing unnecessary occupational exposure.A Case Study of Brass Foundry Workers’ Estimated Lead (Pb) Body Burden from Different Exposure RoutespublishedVersio

Genotoxicity of metal oxide nanomaterials: review of recent data and discussion of possible mechanisms

Nanotechnology has rapidly entered into human society, revolutionized many areas, including technology, medicine and cosmetics. This progress is due to the many valuable and unique properties that nanomaterials possess. In turn, these properties might become an issue of concern when considering potentially uncontrolled release to the environment. The rapid development of new nanomaterials thus raises questions about their impact on the environment and human health. This review focuses on the potential of nanomaterials to cause genotoxicity and summarizes recent genotoxicity studies on metal oxide/silica nanomaterials. Though the number of genotoxicity studies on metal oxide/silica nanomaterials is still limited, this endpoint has recently received more attention for nanomaterials, and the number of related publications has increased. An analysis of these peer reviewed publications over nearly two decades shows that the test most employed to evaluate the genotoxicity of these nanomaterials is the comet assay, followed by micronucleus, Ames and chromosome aberration tests. Based on the data studied, we concluded that in the majority of the publications analysed in this review, the metal oxide (or silica) nanoparticles of the same core chemical composition did not show different genotoxicity study calls (i.e. positive or negative) in the same test, although some results are inconsistent and need to be confirmed by additional experiments. Where the results are conflicting, it may be due to the following reasons: (1) variation in size of the nanoparticles; (2) variations in size distribution; (3) various purities of nanomaterials; (4) variation in surface areas for nanomaterials with the same average size; (5) differences in coatings; (6) differences in crystal structures of the same types of nanomaterials; (7) differences in size of aggregates in solution/media; (8) differences in assays; (9) different concentrations of nanomaterials in assay tests. Indeed, due to the observed inconsistencies in the recent literature and the lack of adherence to appropriate, standardized test methods, reliable genotoxicity assessment of nanomaterials is still challenging

The safe-and-sustainable-by-design concept:innovating towards a more sustainable future

Safe-and-Sustainable-by-Design (SSbD) is a new concept proposed by the European Commission to support the urgent need to transition towards a more preventive and proactive approach in chemical and material innovation which supports a more sustainable future and in meeting the UN’s Sustainable Development Goals. SSbD provides orientation and guidance by taking a system approach. SSbD building blocks were developed: regenerative corporate and societal strategic needs (considering service and function), risk and sustainability governance, competencies, and data management. This viewpoint brings these building blocks together in a holistic way to create an innovation landscape ensuring safer and more sustainable chemicals, materials, production processes and products in science, technology, and industry; starting from ‘design’ and that is fit for supporting a sustainable future

The safe-and-sustainable-by-design concept:innovating towards a more sustainable future

Safe-and-Sustainable-by-Design (SSbD) is a new concept proposed by the European Commission to support the urgent need to transition towards a more preventive and proactive approach in chemical and material innovation which supports a more sustainable future and in meeting the UN’s Sustainable Development Goals. SSbD provides orientation and guidance by taking a system approach. SSbD building blocks were developed: regenerative corporate and societal strategic needs (considering service and function), risk and sustainability governance, competencies, and data management. This viewpoint brings these building blocks together in a holistic way to create an innovation landscape ensuring safer and more sustainable chemicals, materials, production processes and products in science, technology, and industry; starting from ‘design’ and that is fit for supporting a sustainable future

Metal Particles – Hazard or Risk? Elaboration and Implementation of a Research Strategy from a Surface and Corrosion Perspective

Do metal particles (including particles of pure metals, alloys, metal oxides and compounds) pose a hazard or risk to human health? In the light of this question, this thesis summarizes results from research conducted on metal particles, and describes the elaboration and implementation of an in vitro test methodology to study metal release from particles through corrosion and dissolution processes in synthetic biological media relevant for human exposure through inhalation/ingestion and dermal contact. Bioaccessible metals are defined as the pool of released metals from particles that potentially could be made available for absorption by humans or other organisms. Studies of bioaccessible metals from different metal particles within this thesis have shown that the metal release process is influenced by material properties, particle specific properties, size distribution, surface area and morphology, as well as the chemistry of synthetic biological test media simulating various human exposure scenarios. The presence of metal particles in proximity to humans and the fact that metals can be released from particles to a varying extent is the hazard referred to in the title. The bioavailable metal fraction of the released metals (the fraction available for uptake/absorption by humans through different exposure routes) is usually significantly smaller than the bioaccessible pool of released metals, and is largely related to the chemical form and state of oxidation of the released metals. Chemical speciation measurements of released chromium for instance revealed chromium to be complexed to its non-available form in simulated lung fluids. Such measurements provide an indirect measure of the potential risk for adverse health effects, when performed at relevant experimental conditions. A more direct way to assess risks is to conduct toxicological in-vitro testing of metal particles, for instance on lung cell cultures relevant for human inhalation. Induced toxicity of metal particles on lung cells includes both the effect of the particles themselves and of the released metal fraction (including bioaccessible and bioavailable metals), the latter shown to be less predominant. The toxic response was clearly influenced by various experimental conditions such as sonication treatment of particles and the presence of serum proteins. Thorough characterization of metal particles assessing parameters including chemical surface composition, degree of agglomeration in solution, size distribution, surface area and morphology was performed and discussed in relation to generated results of bioaccessibility, bioavailability and induced toxicity. One important conclusion was that neither the surface composition nor the bulk composition can be used to assess the extent of metals released from chromium-based alloy particles. These findings emphasize that information on physical-chemical properties and surface characteristics of particles is essential for an in-depth understanding of metal release processes and for further use and interpretation of bioaccessibility data to assess hazard and reduce any risks induced by human exposure to metal particles.QC 2010080

Referensmätning av kvartsdamm inom väg- och anläggningsprojekt med fokus på arbetsmoment inom losshållning och asfaltfräsning

Kvarts ingår i de vanligast förekommande bergarterna i Sverige och finns därmed i många olika industriella processer som rör bearbetning av exempelvis berggrund, sand, cement och betong. Exponering för kvartsdamm via luftvägarna är hälsoskadligt och kan leda till akuta symptom på silikos (stendammslunga) såväl som kronisk sjukdom lång tid efter exponering (mer än 10 år). Andra sjukdomar som förknippas med kvartsexponering är exempelvis lungcancer, hjärt-kärlsjukdom och kronisk obstruktiv lungsjukdom (KOL). För exponering i arbetsmiljön finns ett nivågränsvärde för respirabel kvarts på 0,1 mg/m3 och i Arbetsmiljöverkets föreskrift AFS 2015:2 Kvarts - stendamm i arbetsmiljön anges att referensmätningar, det vill säga mätresultat vid likvärdiga förhållanden, kan användas för riskbedömning av exponerat arbete. I denna rapport presenteras en ansats att ta fram referensmätningar för utsatta arbetsmoment inom väg- och anläggningsprojekt med fokus på losshållning och asfaltfräsning.Totalt genomfördes 62 personburna mätningar av respirabelt damm vid 18 olika tillfällen under höst/vår samt sommarsäsong. I sammanställningen av resultaten inkluderas även 5 mätresultat för arbetsmoment inom losshållning som genomförts av andra aktörer. Vid mätningarna, som pågick under ett normalt arbetspass, fick deltagarna bära en batteridriven pump som drog luft genom en filterprovtagare med föravskiljare, vilken placerats i andningszonen. Därefter vägdes filtren för bestämning av respirabelt damm och kvartsinnehåll analyserades med röntgendiffraktion. Resultaten visar att samtliga koncentrationer av respirabel kvarts vid olika arbetsmoment inom losshållning var väl under gränsvärdet på 0,1 mg/m3 med några värden uppåt halva gränsvärdet. Även uppmätta halter av respirabelt damm var mycket låga inom losshållning, samtliga under 0,25 mg/m3, en tiondel av gränsvärdet. Koncentrationerna av respirabel kvarts inom asfaltfräsning var generellt under gränsvärdet men varierade i större utsträckning mellan de olika arbetsmomenten i fräslaget, jämfört med uppmätta dammhalter. Högst exponering noterades för deltagare som arbetade med fräsmaskiner utan hytt, samt för deltagare som övervakade fräsningen och därmed rörde sig bredvid pågående arbete. Parallella mätningar vid asfaltfräsning i Skåne och Mälardalen illustrerade betydelsen av kvartsinnehållet i berggrund/råmaterial. Skillnaden mellan mätningarna var tydlig för alla arbetsuppgifter inom fräslagen, med högre andel kvarts i dammet vid fräsning i Skåne. Våra mätningar av respirabel kvarts visade på generellt låga exponeringsnivåer vilket inte föranledde att vidare undersöka effekten av eventuella dammreducerande åtgärder inom projektet. I framtiden vore det intressant att även mäta inhalerbar fraktion för att bättre förstå hur en upplevd dammig arbetsmiljö kan reflekteras i kvarts- och dammhalter av olika partikelstorlek. Att tydliggöra vilka parametrar som är viktigast för att bedöma och hantera risk vid exponerat arbete, är fortsatt viktigt, inte minst när det kommer till att göra referensmätningar praktiskt användbara.Crystalline silica (quartz) is one of the most commonly occurring minerals in Sweden and is thus found in many different industrial processes related to the processing of, for example, bedrock, sand, cement and concrete. Exposure to crystalline silica via the respiratory tract is harmful to health and can lead to acute symptoms of silicosis as well as chronic disease long after exposure (more than 10 years). Other diseases associated with crystalline silica exposure are, for example, lung cancer, cardiovascular disease and chronic obstructive pulmonary disease (COPD). There is an occupational exposure limit value for respirable crystalline silica of 0.1 mg/m3 and in the national regulation, the Swedish Work Environment Authority (AFS 2015:2 Kvarts - stendamm i arbetsmiljön) has opened up for the use of reference measurements, i.e. measurement results under equivalent conditions, in risk assessment of exposed work. This report presents an approach to generate reference measurements for exposed work tasks within road- and construction projects with a focus on extraction of rock (including drilling, blasting etc.) and asphalt milling.A total of 62 personal measurements of respirable dust were carried out on 18 different occasions during the autumn/spring and summer season. The compilation of the results also includes 5 measurement results for drilling and blasting carried out by other actors. During the measurements, which took place during a normal work shift, the participants carried a battery-powered pump that drew air through a filter sampler with a cyclone, which was placed in the breathing zone. The filters were gravimetrically weighed to determine respirable dust and crystalline silica content was analyzed by X-ray diffraction.The results show that all concentrations of respirable crystalline silica at work tasks within rock extraction were well below the limit value of 0.1 mg/m3 with some values above half of the limit value. Measured levels of respirable dust were also very low, all below 0.25 mg/m3, one tenth of the limit value. The concentrations of respirable crystalline silica in asphalt milling were generally below the limit value but varied to a greater extent among the different work tasks within the team, compared to measured dust levels. The highest exposure was noted for participants who worked with milling machines without a cabin, as well as for participants who supervised the milling and thus moved next to work in progress. Parallel measurements during asphalt milling in Skåne and Mälardalen illustrated the importance of the crystalline silica content in bedrock/raw material. The difference between the measurements was clear for all tasks within the milling team, with a higher percentage of crystalline silica in the dust when milling in Skåne. Our measurements of respirable crystalline silica showed generally low exposure levels, which did not lead to further investigation of the possible effect of dust reduction measures. In the future, it would be interesting to also measure the inhalable fraction to better understand how a perceived dusty work environment can be reflected in crystalline silica and dust contents of different particle sizes. To clarify which parameters are most important for assessing and managing risk in exposed work is still important, not least to facilitate and make reference measurements practically useful