Dermal exposure to chemicals in the workplace: just how important is skin absorption?

Moderated mediation role of ethnicity on natural skin care products purchasing intention model among multicultural consumers

The trends for sustainable lifestyle and marketing motivated natural product consumption, such as natural skin care products (NSCPs). Different personal, environmental, and sociocultural factors influence purchase intention (PI) for NSCPs. However, there is a lack of evidence on the role of consumers' ethnicity in the PI model. The present study investigated the moderated mediation role of ethnicity in the relationship between related factors, including environmental concern, subjective norms, health factor, Halal certificate, packaging design, past experience factor, price factor, and PI mediated by personal attitude. A web-based survey was utilized to capture quantitative data from a random sample of 330 multicultural consumer group participants. The results of the study indicated that consumers' ethnicity substantially moderated the mediation effect of personal attitude in the relationships between subjective norms, health factor, Halal certificate, packaging design, past experience factor, price factor, and PI in the model. The findings contributed to understanding of the factors that influenced the PI of consumers from diverse sociocultural contexts in the market for natural products. It contributed directly to natural product marketing and industry.

The association between the incidence of postmenopausal breast cancer and occupational exposure to selected organic solvents, Montreal, Canada, 2008-2011

BACKGROUND

Breast cancer is the most diagnosed cancer among women and recognized risk factors explain 25%-47% of cases. Organic solvents are used widely in the workplace and exposure may increase the risk of developing breast cancer, yet there are insufficient data to confirm this hypothesis. We sought to determine whether past occupational exposures to selected organic solvents were associated with the incidence of invasive breast cancer in postmenopausal women in Montréal, Canada.

METHODS

From a population-based case-control study (2008-2011), using in-depth interviews we elicited information on risk factors and lifetime occupational histories. Industrial hygienists and chemists translated job descriptions into specific chemical and physical exposures. We assessed 11 individual solvents and four solvent groups. Unconditional logistic regression was used to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for metrics of past exposures to selected solvents. Exposure metrics included any previous exposure, average frequency in hours per week, duration in years, and average cumulative concentration weighted by hours per workweek exposed.

RESULTS

We enrolled 695 cases and 608 controls. We found increased ORs for average cumulative concentration of exposure to mononuclear aromatic hydrocarbons (OR: 1.52, 95% CI: 1.04, 2.28), chlorinated alkanes (OR: 2.42, 95% CI: 1.23, 5.68), toluene (OR: 1.59, 95% CI: 1.02, 2.59), and a group of organic solvents with reactive metabolites (OR: 1.53, 95% CI: 1.08, 2.24). Positive associations were found across all exposure metrics and were higher among women with estrogen-positive/progesterone-negative tumors.

CONCLUSION

Our findings suggest occupational exposure to certain organic solvents may increase the risk of incident postmenopausal breast cancer.

Role of hair follicles in the pathogenesis of arsenical-induced cutaneous damage

Arsenical vesicants cause skin inflammation, blistering, and pain. The lack of appropriate animal models causes difficulty in defining their molecular pathogenesis. Here, Ptch1+/- /C57BL/6 mice were employed to investigate the pathobiology of the arsenicals lewisite and phenylarsine oxide (PAO). Following lewisite or PAO challenge (24 h), the skin of animals becomes grayish-white, thick, leathery, and wrinkled with increased bi-fold thickness, Draize score, and necrotic patches. In histopathology, infiltrating leukocytes (macrophages and neutrophils), epidermal-dermal separation, edema, apoptotic cells, and disruption of tight and adherens junction proteins can be visualized. PCR arrays and nanoString analyses showed significant increases in cytokines/chemokines and other proinflammatory mediators. As hair follicles (HFs), which provide an immune-privileged environment, may affect immune cell trafficking and consequent inflammatory responses, we compared the pathogenesis of these chemicals in this model to that in Ptch1+/- /SKH-1 hairless mice. Ptch1+/- /SKH-1 mice have rudimentary, whereas Ptch1+/- /C57BL/6 mice have well-developed HFs. Although no significant differences were observed in qualitative inflammatory responses between the two strains, levels of cytokines/chemokines differed. Importantly, the mechanism of inflammation was identical; both reactive oxygen species induction and consequent activation of unfolded protein response signaling were similar. These data reveal that the acute molecular pathogenesis of arsenicals in these two murine models is similar.

Progress in the field of hydrotropy: mechanism, applications and green concepts

Sustainability and greenness are the concepts of growing interest in the area of research as well as industries. One of the frequently encountered challenges faced in research and industrial fields is the solubility of the hydrophobic compound. Conventionally organic solvents are used in various applications; however, their contribution to environmental pollution, the huge energy requirement for separation and higher consumption lead to unsustainable practice. We require solvents that curtail the usage of hazardous material, increase the competency of mass and energy and embrace the concept of recyclability or renewability. Hydrotropy is one of the approaches for fulfilling these requirements. The phenomenon of solubilizing hydrophobic compound using hydrotrope is termed hydrotropy. Researchers of various fields are attracted to hydrotropy due to its unique physicochemical properties. In this review article, fundamentals about hydrotropes and various mechanisms involved in hydrotropy have been discussed. Hydrotropes are widely used in separation, heterogeneous chemical reactions, natural product extraction and pharmaceuticals. Applications of hydrotropes in these fields are discussed at length. We have examined the significant outcomes and correlated them with green engineering and green chemistry principles, which could give an overall picture of hydrotropy as a green and sustainable approach for the above applications.

MiXie, an Online Tool for Better Health Assessment of Workers Exposed to Multiple Chemicals

There is increasing concern for workers facing multiple chemical exposure. The accumulation of information on occupational conditions indicates the need to incorporate the concept of multiple exposures in the risk assessment process and to develop tools for assessing the potential impacts of multiple exposures on workers’ health. Our objective is to describe the MiXie online decision-making tool that can be used to assess the risk of exposure to multiple chemicals. The description includes the development of MiXie, the structure of its toxicological database according to the target organ or the mode of action, and the algorithm for quantitative analysis of a mixture. Two case studies of its use in evaluating the risks of multiple exposures in real workplace situations are presented. The case study in the printing industry showed increased risk for four toxicological classes (central nervous system damage, ocular damage, skin damage, and ototoxicity) associated with co-exposure to four chemicals during maintenance operations. The MiXie analysis also showed the presence of carcinogenic substances in the mixture and a risk to the development of the foetus. The case study in nail salons showed the presence of carcinogenic and sensitizing chemicals and an increased risk to upper airways. MiXie helps preventers evaluate the possible additive effects of mixtures, providing an easy-to-read diagnosis to identify risks incurred by co-exposed employees. In addition, MiXie identifies risky occupational situations that would go unnoticed without a multiple substance approach.

Prediction of Dermal Exposure to Chemical Substances Using a Fluorescence Method within the SysDEA Project

Dermal exposure is an important exposure route for occupational exposure and risk assessment. A fluorescence method has been developed to quantify occupational dermal exposure based on a visualization technique, using Tinopal SWN as a fluorescent tracer. The method was developed within the framework of a large experimental study, the SysDEA project. In SysDEA, dermal exposure was measured with different methods for 10 simulated exposure situations by sampling powder and liquid formulations containing Tinopal SWN on coveralls and patches and subsequently chemically analysing them. For the fluorescence method, photographs of exposed volunteers who performed the experiments were taken inside a room which consisted of an optimized arrangement of several UV irradiating tube light brackets, reflective and non-reflective backgrounds for maximum light diffusion and a camera. Image processing analysis software processed these photographs to obtain corresponding light intensity in terms of summed pixel values. To be able to estimate the amount of Tinopal SWN, 25% of the measured data from the SysDEA experiments were used to calibrate by correlating the summed pixel values from the photographs to actual measured exposure values using a second order regression model. For spraying both high and low viscosity liquids, showing uniformly distributed exposure patterns, strong Pearson correlation coefficients (R > 0.77) were observed. In contrast, the correlations were either inconsistently poor (R = -0.17 to 0.28 for pouring, rolling high viscosity liquid, manually handling objects immersed in low viscosity liquid and handling objects contaminated with powder), moderate (R = 0.73 for dumping of powder), or strong (R = 0.83 and 0.77 for rolling low viscosity liquid and manually handling objects immersed in high viscosity liquid). A model for spraying was developed and calibrated using 25% of the available experimental data for spraying and validated using the remaining 75%. Under given experimental conditions, the fluorescence method shows promising results and can be used for the quantification of dermal exposure for different body parts (excluding hands) for spraying-like scenarios that have a more uniform exposure pattern, but more research is needed for exposure scenarios with less uniform exposure patterns. For the estimation of exposure levels, the surface loading limit should be lower than 1.5░µg/cm2 (a lower limit could not be quantified based on experiments conducted in this study) on a large surface, like a coverall, which should be ideally perpendicular to the camera.

A review of new adsorbents for separation of BTEX biomarkers

The biomarker analysis of benzene, toluene, ethylbenzene and xylene (BTEXs) in biological samples is the primary technique for evaluating these compounds in occupational and environmental exposures. The BTEX biomarkers are widely used to study the BTEX distribution in the environment and workplaces. Liquid-liquid extraction and solid-phase liquid extraction are among the most commonly used conventional methods to analyze biological indices of BTEXs. New methods have been proposed to analyze BTEX biomarkers using novel adsorbents such as sol-gel composite nanotubes, molecularly imprinted polymers and metal-organic frameworks, which are based on the application of needle trap devices, microextraction by packed sorbent, and solid-phase microextraction techniques. This paper provides an overview of new methods since 2015 regarding applying microextraction methods based on new adsorbents and analyzing BTEX biomarker compounds for occupational and environmental exposures. The results were compared with the liquid-phase microextraction methods recommended for urinary BTEX biomarkers.

Measuring Environmental Exposure to Enteric Pathogens in Low-Income Settings: Review and Recommendations of an Interdisciplinary Working Group

Infections with enteric pathogens impose a heavy disease burden, especially among young children in low-income countries. Recent findings from randomized controlled trials of water, sanitation, and hygiene interventions have raised questions about current methods for assessing environmental exposure to enteric pathogens. Approaches for estimating sources and doses of exposure suffer from a number of shortcomings, including reliance on imperfect indicators of fecal contamination instead of actual pathogens and estimating exposure indirectly from imprecise measurements of pathogens in the environment and human interaction therewith. These shortcomings limit the potential for effective surveillance of exposures, identification of important sources and modes of transmission, and evaluation of the effectiveness of interventions. In this review, we summarize current and emerging approaches used to characterize enteric pathogen hazards in different environmental media as well as human interaction with those media (external measures of exposure), and review methods that measure human infection with enteric pathogens as a proxy for past exposure (internal measures of exposure). We draw from lessons learned in other areas of environmental health to highlight how external and internal measures of exposure can be used to more comprehensively assess exposure. We conclude by recommending strategies for advancing enteric pathogen exposure assessments.

Human in vitro percutaneous absorption of bisphenol S and bisphenol A: A comparative study

Bisphenol A (BPA) is widely used in industrial products. Due to the toxicity of this compound, and to comply with restrictions and regulations, manufacturers have progressively replaced it by substitutes. One of the main substitutes used is bisphenol S (BPS). Despite increasing use in many products, the effects of BPS on human health have been little investigated, and studies on percutaneous BPS absorption and particularly toxicokinetic data are lacking. However, the endocrine-disrupting activity of BPA and BPS appears comparable. Dermal contact is a significant source of occupational exposure and is the main route during handling of bisphenol-containing receipts by cashiers. Here, percutaneous BPS absorption was investigated and compared to that of BPA. Experiments were performed according to OECD guidelines. Test compounds dissolved in a vehicle - acetone, artificial sebum or water - were applied in vitro to fresh human skin samples in static Franz diffusion cells. Flux, cumulative absorbed dose and distribution of dose recovered were measured. BPA absorption was vehicle-dependent ranging from 3% with sebum to 41% with water. BPS absorption was much lower than BPA absorption whatever the vehicle tested (less than 1% of applied dose). However, depending on the vehicle 20% to 47% of the applied BPS dose remained in the skin, and was consequently potentially absorbable. Both BPA and BPS were mainly absorbed without biotransformation. Taken together, these results indicate that workers may be exposed to BPS through skin when handling products containing it. This exposure is of concern as its toxicity is currently incompletely understood.

Spatially high-resolved monitoring and risk assessment of polycyclic aromatic hydrocarbons in an industrial city

Polycyclic aromatic hydrocarbons (PAHs) were monitored at 20 sites in semi-rural, urban, and industrial areas of Ulsan, the largest industrial city in South Korea, for one year. The target compounds were the 16 priority PAHs designated by the US Environmental Protection Agency except for naphthalene, acenaphthene, and acenaphthylene. Gaseous PAHs collected using polyurethane foam-based passive air samplers (PUF-PASs) and particulate PAHs predicted using gas/particle partitioning models were used to estimate the human health risks. The mean total cancer risk through inhalation intake and dermal absorption for all target age groups (children, adolescents, adults, and lifetime) ranged from 0.10 × 10^-7 to 2.62 × 10^-7, lower than the acceptable risk level (10^-6), thus representing a safe level for residents. The cancer risk through dermal absorption and inhalation intake was predicted to be highest in winter, mostly due to the higher concentrations of PAHs, especially high-molecular-weight species with greater toxicity. Additionally, gaseous and particulate PAHs contributed more to dermal absorption and inhalation intake, respectively. As a consequence of local emissions and advection, the risks were higher in the industrial and semi-rural areas. This study suggests that human health risks can be cost-effectively mapped on a local scale using passive air sampling.

Interception Systems in Assessment of Dermal Exposure to Pesticides: Laboratory Comparison of Media

Dermal exposure of workers to pesticides can be assessed using patches, placed on the workers' clothes or used to wipe off the substance from the skin. Since there are no official indications of the materials to be used for patch sampling, a wide range of materials is suggested in the scientific literature. This paper reports a laboratory study on the affinity of four different pesticides widely used in southern Italy with five patch matrices. Imidacloprid, Hexythiazox, Boscalid and Myclobutanil were tested with cotton and gauze sheets, polyethylene tissue and two different grades of cellulose papers. An aerosol machine was used to nebulize the substance on the patches in a closed system, simulating the conditions of use on the workers' clothes. The recovery of the analytes from the media was evaluated, by spiking the patches with a known amount of each active substance and testing their performances as skin wipes. Samples were extracted and analyzed in gas chromatography with an electron capture detector. The recovery from the spiked patches was 89-96% for all pesticides, while the test recoveries were very different. Results showed a higher affinity with Imidacloprid and Hexythiazox for gauze, with Myclobutanil for cotton and with Boscalid for paper filters (W41).

Cancer risk among career male and female Florida firefighters: Evidence from the Florida Firefighter Cancer Registry (1981-2014)

BACKGROUND

Firefighters are at increased risk for select cancers. However, many studies are limited by relatively small samples, with virtually no data on the cancer experience of female firefighters. This study examines cancer risk in over 100,000 career Florida firefighters including 5000 + females assessed over a 34-year period.

METHODS

Florida firefighter employment records (n = 109 009) were linked with Florida Cancer Data System registry data (1981-2014; ~3.3 million records), identifying 3760 male and 168 female-linked primary cancers. Gender-specific age and calendar year-adjusted odds ratios (aOR) and 95% confidence intervals for firefighters vs non-firefighters were calculated.

RESULTS

Male firefighters were at increased risk of melanoma (aOR = 1.56; 1.39-1.76), prostate (1.36; 1.27-1.46), testicular (1.66; 1.34-2.06), thyroid (2.17; 1.78-2.66) and late-stage colon cancer (1.19;1.00-1.41). Female firefighters showed significantly elevated risk of brain (2.54; 1.19-5.42) and thyroid (2.42; 1.56-3.74) cancers and an elevated risk of melanoma that approached statistical significance (1.68; 0.97-2.90). Among male firefighters there was additional evidence of increased cancer risk younger than the age of 50 vs 50 years and older for thyroid (2.55; 1.96-3.31 vs 1.69; 1.22-2.34), prostate (1.88; 1.49-2.36 vs 1.36; 1.26-1.47), testicular (1.60; 1.28-2.01 vs 1.47; 0.73-2.94), and melanoma (1.87; 1.55-2.26 vs 1.42; 1.22-1.66) cancers.

CONCLUSION

Male career firefighters in Florida are at increased risk for five cancers with typically stronger associations in those diagnosed younger than the age of 50, while there was evidence for increased thyroid and brain cancer, and possibly melanoma risk in female firefighters. Larger cohorts with adequate female representation, along with the collection of well-characterized exposure histories, are needed to more precisely examine cancer risk in this occupational group.

Comparison of Measurement Methods for Dermal Exposure to Hazardous Chemicals at the Workplace: The SysDEA Project

There is a principal need for more precise methodology with regard to the determination of occupational dermal exposure. The goal of the Systematic analysis of Dermal Exposure to hazardous chemical Agents at the workplace project was therefore to generate scientific knowledge to improve and standardize measurement methods for dermal exposure to chemicals at the workplace. In addition, the comparability of different measurement methods was investigated. Different methods (body sampling by means of coveralls and patches, hand sampling by means of gloves and washing, and head sampling by means of headbands and wiping) were compared. Volunteers repeatedly performed a selection of tasks under standardized conditions in test chambers to increase the reproducibility and decrease variability. The selected tasks were pouring, rolling, spraying, and handling of objects immersed in liquid formulations, as well as dumping and handling objects contaminated with powder. For the chemical analysis, the surrogate test substance Tinopal SWN was analyzed by means of a high-performance liquid chromatographic method using a fluorescence detector. Tinopal SWN was either applied as a solid product in its pure form, or as a low and high viscosity liquid containing Tinopal SWN in dissolved form. To compare the sampling methods with patches and coveralls, the exposure values as measured on the patches were extrapolated to the surface areas of the respective parts of the coverall. Based on this extrapolation approach, using the patch method resulted in somewhat higher exposure values compared to using a coverall for all exposure situations, but the differences were only statistically significant in case of the liquid exposure situations. Using gloves resulted in significantly higher exposure values compared to hand wash for handling immersed objects, rolling, and handling contaminated objects, and slightly higher (not significant) exposure values during pouring and spraying. In the same context, applying wipe sampling resulted in higher exposure values than using a headband, which was at least partly due to extrapolation of the wipe results to the surface area of the headband. No ‘golden standard’ with regard to a preferred measurement method for dermal exposure could be identified from the methods as investigated in the current study.

Airborne Particulate Matter: Human Exposure and Health Effects

OBJECTIVE

Exposure to airborne particulate matter (PM) is estimated to cause millions of premature deaths annually. This work conveys known routes of exposure to PM and resultant health effects.

METHODS

A review of available literature.

RESULTS

Estimates for daily PM exposure are provided. Known mechanisms by which insoluble particles are transported and removed from the body are discussed. Biological effects of PM, including immune response, cytotoxicity, and mutagenicity, are reported. Epidemiological studies that outline the systemic health effects of PM are presented.

CONCLUSION

While the integrated, per capita, exposure of PM for a large fraction of the first-world may be less than 1 mg per day, links between several syndromes, including attention deficit hyperactivity disorder (ADHD), autism, loss of cognitive function, anxiety, asthma, chronic obstructive pulmonary disease (COPD), hypertension, stroke, and PM exposure have been suggested. This article reviews and summarizes such links reported in the literature.

Safety and health index development for formulated product design: Paint formulation

Over the years, safety and health effects among consumers due to the exposure of formulated products have been reported. Thus, there is a need for systematic methodologies to assess the safety and health effects of the candidate’s ingredients in the early stages of formulated product design. Therefore, an index-based methodology was proposed to assess the safety and health effects in formulated product design. Product Safety and Health Index (PSHI) highlights the health sub-indexes based on the exposure routes including eye, inhalation, ingestion, and dermal. Each exposure route has its corresponding health sub-indexes that have to be applied. There are also new sub-indexes introduced for ingestion and dermal exposure. A case study on paint formulation was used to illustrate the developed methodology. The results show that the newly proposed index is able to identify hazardous chemical ingredient(s) with its corresponding adverse safety and health effects.

The Dermal Exposure Risk Management and Logic eTookit: Characterizing and managing dermal exposure during emergency management operations

OBJECTIVE

Emergency management and operations (EMO) personnel require up-to-date information to make informed decisions during natural and man-made disasters. However, information gaps present challenges for accessing human health risk assessment and risk management strategies for dermal exposure. This article describes the development of a decision support system, the Dermal Exposure Risk Management and Logic (DERMaL) eToolkit.

DESIGN

The DERMaL eToolkit provides information on key resources used in emergency incidents. Resources were classified according to response phase, resource categories, and information category and evaluated on reliability, accessibility, and preference by subject matter experts in emergency management fields. These rankings were used to generate a value of information score, unique for each resource, which aids in developing reference lists for users during each incident phase.

RESULTS

This tool will identify and prioritize information resources on dermal risks, and can readily find the most relevant information to suit EMO needs.

CONCLUSION

The DERMaL eToolkit can be used as an aid in finding information resources targeted to scenario-driven needs by providing well-vetted and prioritized resources related to dermal hazards, exposure, and risk assessments for EMO.

Effects of Personal Protective Equipment Use and Good Workplace Hygiene on Symptoms of Neurotoxicity in Solvent-Exposed Vehicle Spray Painters

Objectives

To assess the association between the use of personal protective equipment (PPE) and good workplace hygiene and symptoms of neurotoxicity in solvent-exposed vehicle spray painters.

Methods

Exposure control measures including PPE-use and workplace hygiene practices and symptoms of neurotoxicity were assessed in 267 vehicle repair spray painters. Symptoms were assessed using an adapted version of the EUROQUEST Questionnaire.

Results

Frequent respirator and glove use was inversely and significantly associated with symptoms of neurotoxicity in a dose-dependent manner (P < 0.05 for trend) with the strongest protective effect found for consistent glove use (odds ratios [OR] 0.1-0.2, P < 0.01, for reporting ≥10 and ≥5 symptoms). A clear dose-response trend was also observed when combining frequency of respirator and glove use (P < 0.05 for reporting ≥5 and ≥10 symptoms), with an overall reduction in risk of 90% (OR, 0.1, P < 0.01) for those who consistently used both types of PPE. Protective effects were most pronounced for the symptom domains of psychosomatic (P < 0.05 for trend, for combined PPE use), mood (P < 0.05), and memory and concentration symptoms combined (P < 0.05), with reductions in risk of >80%. Poor hygiene workplace practices, such as solvent exposure to multiple body parts (OR 3.4, P = 0.11 for reporting ≥10 symptoms), were associated with an increased risk of symptoms. When using a general workplace hygiene score derived from a combination of PPE-use and (good) workplace practice factors an inverse and significant dose-response trend was observed for reporting ≥5 (P < 0.01) and ≥10 symptoms (P < 0.01).

Conclusions

This study has shown that PPE-use and good workplace hygiene are associated with a strongly reduced risk of symptoms of neurotoxicity in solvent-exposed vehicle spray painters.

Occupational Health and the Visual Arts: An Introduction

OBJECTIVE

Occupational hazards in the visual arts often involve hazardous materials, though hazardous equipment and hazardous work conditions can also be found. Occupational health professionals are familiar with most of these hazards and are particularly qualified to contribute clinical and preventive expertise to these issues.

METHODS

Articles illustrating visual arts health issues were sought and reviewed. Literature sources included medical databases, unindexed art-health publications, and popular press articles.

RESULTS

Few medical articles examine health issues in the visuals arts directly, but exposures to pigments, solvents, and other hazards found in the visual arts are well described. The hierarchy of controls is an appropriate model for controlling hazards and promoting safer visual art workplaces.

CONCLUSIONS

The health and safety of those working in the visual arts can benefit from the occupational health approach. Sources of further information are available.

Pattern of acute organophosphorus poisoning at University of Gondar Teaching Hospital, Northwest Ethiopia

Background

Despite the apparent benefits of organophosphate compounds (OPCs) acute organophosphate (OP) pesticide poison is an increasing problem worldwide. In a country like Ethiopia, where agriculture is a major component of the economy, these compounds are readily available to the general public. There is paucity of evidence from Ethiopia showing the pattern of organophosphate poisoning (OPP) in healthcare facilities. The objective of this study was to evaluate retrospectively the pattern of acute OPP at the University of Gondar Teaching Hospital in northwest Ethiopia, during September 2010 through December 2014 was conducted. Data was collected through chart review of patients who were admitted due to poisoning. Data was analysed using SPSS 20.

Results

Organophosphate poisoning in University of Gondar teaching hospital accounts for about 38.46% of all emergency room admissions for poisoning. Out of the 90 cases studied 60% (54) were women, with male to female ratio of 1:1.5. The mean age of the patients was 25.5 with a standard deviation of 9.45. 56.7% of the cases studies lived in an urban environment compared to 43.3% who lived rurally. In the vast majority of patients, 90% (81) patients had ingested OP as an act of suicide. Regarding the route of exposure, oral ingestion was most common in suicidal cases (88.9%). The elapsed time between the time of poison ingestion and the start of the treatment, ranged from 13 min to 1 day. Health care professionals’ useds decontamination methods such as gastric lavage and activated charcoal (45.6%) and 36.7% use atropine for OPP treatment. The mean hospital stay was 0.74 days. In the present study family problems were a leading cause of suicides and accounted for 45.8% of all cases.

Conclusion

As a developing nation who economy relies heavily on agriculture, Ethiopia continues to have OP compounds remain a common cause of acute poisonings. This is particularly concerning for younger generation who have high rates of OPP and whose numbers continue to raise. This data suggests that it is essential to strengthen Ethiopians regulatory policy concerning the availability of OPCs. Additionally, it will be important to design an appropriate health education program for the prevention of both suicidal and accidental OPPs for the benefit of the public at large.

Electronic supplementary material

The online version of this article (doi:10.1186/s13104-017-2464-5) contains supplementary material, which is available to authorized users.

Dermal Uptake from Airborne Organics as an Important Route of Human Exposure to E-Waste Combustion Fumes

Skin absorption of gaseous organic contaminants is an important and relevant mechanism in human exposure to such contaminants, but has not been adequately examined. This article demonstrates that dermal uptake from airborne contaminants could be recognized as a significant exposure route for local residents subjecting to combustion fume from e-waste recycling activities. It is particularly true for organic pollutants which have high dermal penetration rates and large skin-air partition coefficients, such as low molecular weight plasticizers and flame retardants.

Background Noise Contributes to Organic Solvent Induced Brain Dysfunction

Occupational exposure to complex blends of organic solvents is believed to alter brain functions among workers. However, work environments that contain organic solvents are also polluted with background noise which raises the issue of whether or not the noise contributed to brain alterations. The purpose of the current study was to determine whether or not repeated exposure to low intensity noise with and without exposure to a complex blend of organic solvents would alter brain activity. Female Fischer344 rats served as subjects in these experiments. Asynchronous volume conductance between the midbrain and cortex was evaluated with a slow vertex recording technique. Subtoxic solvent exposure, by itself, had no statistically significant effects. However, background noise significantly suppressed brain activity and this suppression was exacerbated with solvent exposure. Furthermore, combined exposure produced significantly slow neurotransmission. These abnormal neurophysiologic findings occurred in the absence of hearing loss and detectable damage to sensory cells. The observations from the current experiment raise concern for all occupations where workers are repeatedly exposed to background noise or noise combined with organic solvents. Noise levels and solvent concentrations that are currently considered safe may not actually be safe and existing safety regulations have failed to recognize the neurotoxic potential of combined exposures.

A Web-based Tool to Aid the Identification of Chemicals Potentially Posing a Health Risk through Percutaneous Exposure

Occupational hygiene practitioners typically assess the risk posed by occupational exposure by comparing exposure measurements to regulatory occupational exposure limits (OELs). In most jurisdictions, OELs are only available for exposure by the inhalation pathway. Skin notations are used to indicate substances for which dermal exposure may lead to health effects. However, these notations are either present or absent and provide no indication of acceptable levels of exposure. Furthermore, the methodology and framework for assigning skin notation differ widely across jurisdictions resulting in inconsistencies in the substances that carry notations. The UPERCUT tool was developed in response to these limitations. It helps occupational health stakeholders to assess the hazard associated with dermal exposure to chemicals. UPERCUT integrates dermal quantitative structure-activity relationships (QSARs) and toxicological data to provide users with a skin hazard index called the dermal hazard ratio (DHR) for the substance and scenario of interest. The DHR is the ratio between the estimated 'received' dose and the 'acceptable' dose. The 'received' dose is estimated using physico-chemical data and information on the exposure scenario provided by the user (body parts exposure and exposure duration), and the 'acceptable' dose is estimated using inhalation OELs and toxicological data. The uncertainty surrounding the DHR is estimated with Monte Carlo simulation. Additional information on the selected substances includes intrinsic skin permeation potential of the substance and the existence of skin notations. UPERCUT is the only available tool that estimates the absorbed dose and compares this to an acceptable dose. In the absence of dermal OELs it provides a systematic and simple approach for screening dermal exposure scenarios for 1686 substances.

A decision support framework for characterizing and managing dermal exposures to chemicals during Emergency Management and Operations

Emergency Management and Operations (EMO) personnel are in need of resources and tools to assist in understanding the health risks associated with dermal exposures during chemical incidents. This article reviews available resources and presents a conceptual framework for a decision support system (DSS) that assists in characterizing and managing risk during chemical emergencies involving dermal exposures. The framework merges principles of three decision-making techniques: 1) scenario planning, 2) risk analysis, and 3) multicriteria decision analysis (MCDA). This DSS facilitates dynamic decision making during each of the distinct life cycle phases of an emergency incident (ie, preparedness, response, or recovery) and identifies EMO needs. A checklist tool provides key questions intended to guide users through the complexities of conducting a dermal risk assessment. The questions define the scope of the framework for resource identification and application to support decision-making needs. The framework consists of three primary modules: 1) resource compilation, 2) prioritization, and 3) decision. The modules systematically identify, organize, and rank relevant information resources relating to the hazards of dermal exposures to chemicals and risk management strategies. Each module is subdivided into critical elements designed to further delineate the resources based on relevant incident phase and type of information. The DSS framework provides a much needed structure based on contemporary decision analysis principles for 1) documenting key questions for EMO problem formulation and 2) a method for systematically organizing, screening, and prioritizing information resources on dermal hazards, exposures, risk characterization, and management.

Tremor secondary to neurotoxic exposure: mercury, lead, solvents, pesticides

Lead, mercury, solvents, and pesticide exposures are common in certain occupations and may cause nervous system dysfunction. Tremors may be the herald manifestation among a constellation of acute toxicity signs and symptoms. However, since tremors may also be the only sign on clinical presentation and since tremors also occur in other diseases, relating tremors to a specific occupational exposure can be challenging. Diagnosis of tremor etiology must be based on other findings on physical exam, laboratory results, and/or imaging. Discerning whether the tremor resulted from the occupational environment versus other etiologies requires knowledge of potential exposure sources, additional detail in history taking, and support of other health and industrial professionals. Reduction or removal from the exposure source remains the key first step in treating patients suffering from tremor that had resulted from occupational exposure toxicity.

Benzene exposure among auto-repair workers from workplace ambience: a pioneer study from Pakistan

OBJECTIVES

In Pakistan, the reports on benzene exposure among workers in chemical industries are almost non-existing due to limited research work in the field of exposure science. This study aimed to investigate such exposure in a widely adopted occupation in Rawalpindi city.

MATERIAL AND METHODS

In this cross-sectional study, 60 blood samples (N = 20/group) of mechanics (MCs), spray painters (PNs) and control participants (CN) were analyzed. The socio-economic and demographic information of workers and that of workplaces was documented using a short questionnaire.

RESULTS

We identified that the workers in spray-painting occupation are highly at risk of benzene exposure. The results showed that PNs were more at risk of exposure to benzene than MCs, and this exposure was significantly correlated with long working hours (r = 0.68, p < 0.001). Moreover, there are several limitations in workplace setups, which need to be addressed in order to mitigate workers health risk in this occupation. In addition to the reckless use of chemicals, other identified predictors of exposure included active and passive smoking, poor workplace hygiene and substandard ventilation.

CONCLUSIONS

To mitigate workplace exposure, it is necessary to reduce working hours and encourage regular use of self-protective equipments and adoption of proper hygiene in chemical workplaces.

A framework incorporating the impact of exposure scenarios and application conditions on risk assessment of chemicals applied to skin

PURPOSE

1. To develop a framework for exposure calculation via the dermal route to meet the needs of 21st century toxicity testing and refine current approaches; 2. To demonstrate the impact of exposure scenario and application conditions on the plasma concentration following dermal exposure.

METHOD

A workflow connecting a dynamic skin penetration model with a generic whole-body physiologically-based pharmacokinetic (PBPK) model was developed. The impact of modifying exposure scenarios and application conditions on the simulated steady-state plasma concentration and exposure conversion factor was investigated for 9 chemicals tested previously in dermal animal studies which did not consider kinetics in their experimental designs.

RESULTS

By simulating the animal study scenarios and exposure conditions, we showed that 7 studies were conducted with finite dose exposures, 1 with both finite and infinite dose exposures (in these 8 studies, an increase in the animal dose resulted in an increase in the simulated steady-state plasma concentrations (C p,ss)), while 1 study was conducted with infinite dose exposures only (an increase in the animal dose resulted in identical C p,ss). Steady-state plasma concentrations were up to 30-fold higher following an infinite dose scenario vs. a finite dose scenario, and up to 40-fold higher with occlusion vs. without. Depending on the chemical, the presence of water as a vehicle increased or decreased the steady-state plasma concentration, the largest difference being a factor of 16.

CONCLUSIONS

The workflow linking Kasting's model of skin penetration and whole-body PBPK enables estimation of plasma concentrations for various applied doses, exposure scenarios and application conditions. Consequently, it provides a quantitative, mechanistic tool to refine dermal exposure calculations methodology for further use in risk assessment.

Dermal exposure to chemicals - evaluation of skin barrier damage

Dermal exposure to xenobiotic compounds occurs on a daily basis in many humans, in intended as well as unintended ways. Serious skin problems are caused by household chemical products, mainly by strong anionic surfactants. The purpose of this study was to assess the suitability of two in vitro methods for evaluation of sodium lauryl sulphate (SLS) potential on skin barrier damage. Transdermal electrical conductivity (TEC) according to our design, and the method of in vitro skin permeability of indigotine as a chemical skin integrity marker were used. The TEC values across the skin membrane damaged with 5, 10 and 15 % aqueous SLS solutions for 1 h were 3.92, 5.79, and 7.29-fold higher respectively than the data of TEC across the intact skin membrane. The amounts of indigotine after 20 h permeation through the skin membrane damaged with 5, 10 and 15 % SLS were 2.48, 4.04, and 5.81-fold higher respectively than the measured amount of indigotine permeated through the intact skin. We consider that the measurement of TEC, especially, in combination with a suitable chemical marker can be simple, quick, safe and cost effective in vitro method for prediction the skin barrier damage not only by surfactants, but also for hazard and risk evaluation of other chemical compounds the human skin is exposed to.

Absorption of chemicals through compromised skin

Skin is an important route of entry for many chemicals in the work place. To assess systemic uptake of a chemical in contact with the skin, quantitative information on dermal absorption rates of chemicals is needed. Absorption rates are mainly obtained from studies performed with intact, healthy skin. At the work place, however, a compromised skin barrier, although not necessarily visible is common, e.g. due to physical and chemical damage. As reviewed in this article, there are several lines of evidence that reduced integrity of the skin barrier may increase dermal absorption of chemicals in the occupational setting. An impaired skin barrier might lead not only to enhanced absorption of a specific chemical, but also to entrance of larger molecules such as proteins and nanoparticles which normally are not able to penetrate intact skin. In addition to environmental influences, there is increasing evidence that some individuals have an intrinsically affected skin barrier which will facilitate entrance of chemicals into and through the skin making these persons more susceptible for local as well for systemic toxicity. This review addresses mechanisms of barrier alteration caused by the most common skin-damaging factors in the occupational settings and the consequences for dermal absorption of chemicals. Furthermore, this review emphasizes the importance of maintained barrier properties of the skin.

Dermal permeation of biocides and aromatic chemicals in three generic formulations of metalworking fluids

Metalworking fluids (MWF) are complex mixtures consisting of a variety of components and additives. A lack of scientific data exists regarding the dermal permeation of its components, particularly biocides. The aim of this study was to evaluate the dermal permeation of biocides and other aromatic chemicals in water and in three generic soluble oil, semi-synthetic, and synthetic MWF types in order to evaluate any differences in their permeation profiles. An in vitro flow-through diffusion cell study was performed to determine dermal permeation. An infinite dose of different groups of chemicals (6 biocides and 29 aromatic chemicals) was applied to porcine skin, with perfusate samples being collected over an 8-h period. Perfusate samples were analyzed by gas chromatography/mass spectrometry (GC-MS) and ultra-performance liquid chromatography/mass spectroscopy (UPLC-MS), and permeability was calculated from the analysis of the permeated chemical concentration-time profile. In general, the permeation of chemicals was highest in aqueous solution, followed by synthetic, semi-synthetic, and soluble oil MWF. The absorption profiles of most of the chemicals including six biocides were statistically different among the synthetic and soluble oil MWF formulations, with reduced permeation occurring in oily formulations. Permeation of almost all chemicals was statistically different between aqueous and three MWF formulation types. Data from this study show that permeation of chemicals is higher in a generic synthetic MWF when compared to a soluble oil MWF. This indicates that a soluble oil MWF may be safer than a synthetic MWF in regard to dermal permeation of chemicals to allow for an increased potential of systemic toxicity. Therefore, one may conclude that a synthetic type of formulation has more potential to produce contact dermatitis and induce systemic toxicological effects. The dilution of these MWF formulations with water may increase dermal permeability of biocides, allowing for an enhanced risk for systemic toxicological effects and dermatitis potential.

Symptom screening in detection of occupational solvent-related encephalopathy

OBJECTIVES

Sensitive and easily applicable methods are needed for early detection of central nervous system adverse effects related to occupational solvent exposure. The present study evaluates how symptom screening works in practice.

METHODS

A cross-sectional questionnaire survey was conducted on 2,000 construction workers, including painters and carpenters, in Finland. Scores were calculated for symptoms relevant for chronic solvent encephalopathy (CSE). Responses on exposure and health were compared between subjects with high score (N = 28) and all other respondents. The respondents with the highest scores, regardless of their occupation and exposure, were invited for clinical examination to investigate the aetiologies of the symptoms. If the examination resulted in a suspicion of CSE, a multidisciplinary differential diagnostic follow-up procedure was performed.

RESULTS

The respondents with highest symptom scores were more exposed to solvents than those with lower scores (P < 0.001) and reported more often physician-diagnosed diseases, especially psychiatric disorders (P < 0.001). They also consumed more alcohol (P = 0.005) and were more often unemployed or unable to work (P < 0.001). In the clinical examination, sleep disturbances, somatic disorders, depression, unemployment, and alcohol use were commonly found in addition to considerable solvent exposure history and clinical neurological findings. Further examinations and a diagnostic follow-up verified three cases of encephalopathy. One case was a CSE, an occupational disease. The other two encephalopathy cases had multifactorial aetiology including solvents.

CONCLUSIONS

Screening in active workforce for symptoms of cognitive dysfunction identifies highly solvent-exposed workers and also reveals occupational and non-occupational cases of encephalopathy. Evaluation of differential diagnostic conditions is essential in the detection of CSE. A stepwise model is proposed.

Rapid method for determining dermal exposures to pesticides by use of tape stripping and FTIR spectroscopy: a pilot study

Tape stripping is a common method for estimating dermal exposure to pesticides because it is relatively noninvasive and easy to use. A major disadvantage is that samples are usually analyzed with gas chromatography, a time-consuming method in terms of sample preparation. In this study, the authors evaluated the feasibility of using Fourier transform infrared spectroscopy (FTIR) to analyze tape stripped samples to provide near real-time dermal exposure estimates. Various exposure scenarios were evaluated, including a single chemical (i.e., chlorpyrifos, a commonly used pesticide) and a mixture of two chemicals (i.e., chlorpyrifos and captan); these were analyzed with or without the human stratum corneum in the samples. Infrared transparent tape was used for sample collection; samples were analyzed using a FTIR spectrometer in the transmittance mode. The partial least squares algorithm was applied to quantify the spectra and the respective R(2) values for calibration, and test samples were larger than 0.99 and 0.90. The percent divergence of this approach was mostly below 10%, except for several low loading samples. The ANOVA test showed that the stratum corneum's influence on the percent divergence was not significant. Although all the samples evaluated in this study were collected from the same human subject, advantages and feasibility of the stripping-FTIR approach were demonstrated.