Dermal Exposure Levels Research Articles

Bystander dermal exposure to drift during pesticide application in vineyards: an experimental factorial study.

Although public concerns about their exposure to agricultural pesticides and the potential impacts on their health began to gain momentum around the early 2000s, there is limited data on the direct exposure of bystanders to spray drift through the deposition of drift droplets on the skin. To address these knowledge gaps in vineyards, trials were conducted on a test bench using artificial vegetation and wind. Different spraying technologies and drift mitigation measures, such as air-induction nozzles or hedgerows along the vineyard margin, were compared. Sulforhodamine B was used as a fluorescent tracer to mimic pesticide contamination under real-use conditions. In total 72 t-shirts on manikins were used, resulting in 144 cotton collectors (arms and torsos) for extracting the tracer. The dermal exposure levels were expressed in μL spray and compared using nonparametric ANOVA analyses in a factorial experimental framework. All the factor and interaction terms had a highly significant effect (p<10-6) on the exposure level. There was an exponential-like decay in the average exposure with distance (3.3, 5, 10 and 20 m, respectively). In terms of sprayers, a noticeable trend was observed with drift reduction technology. The presence of a hedgerow had a substantial effect, flattening the exposure curves with distance, regardless of the sprayer. This study produced realistic bystander exposure levels for different combinations involving the presence of a hedgerow, distances and drift reduction devices. Before entering these data into refined risk assessment models for grapevine production, hedgerows should be characterized more thoroughly, while accounting for potential secondary drift.

Health risk assessment of surface water resources in the Nandom Municipality of Ghana

In Northern Ghana, reservoirs/dug-outs provide immeasurable services regardless of the season. A study was conducted in Kokoliguo and Nandom-Guo to evaluate health risks from exposure to surface waters. Samples were analyzed for pH, turbidity, conductivity, zinc (Zn), iron (Fe), manganese (Mn), copper (Cu), cadmium (Cd) and lead (Pb). Kokoliguo revealed mean levels of 7.52 pH units, 124 NTU, 89.6 µS/cm, 0.004 mg/L (Zn), 0.210 mg/L (Fe), 0.219 mg/L (Mn), 0.007 mg/L (Cu), 0.007 mg/L (Cd) and 0.001 mg/L (Pb). Nandom-Guo recorded mean levels of 7.72 pH units, 11.6 NTU, 240 µS/cm, 0.0375 mg/L (Zn), 0.601 mg/L (Fe), 0.220 mg/L (Mn), 0.009 mg/L (Cu), 0.003 mg/L (Cd) and 0.182 mg/L (Pb). The chronic daily intakeoral for Kokoliguo and Nandom-Guo users occurred in the order; Cu < Cd < Zn < Mn < Fe and Cu < Cd < Zn` < Mn < Fe, respectively. Dermal exposure for Kokoliguo and Nandom-Guo occurred in the order; Zn < Cu < Cd < Mn < Fe and Cd < Zn < Cu < Mn < Fe, respectively. Except for Kokoliguo, hazard index derm/oral fell below 1. Cancer riskoral level of Cd exceeded 10e−04 among users. On the contrary, cancer riskoral levels of Pb ranged from 10e−04 to 10e−07 whereas dermal exposure levels ranged from 10e−09—10e−07. The cancer riskoral values predict the risk of carcinogenesis due to Cd toxicity. This study recommends crop farmers desist from the use of synthetic fertilizers. Again, improved water sources should be developed for the communities for domestic uses.

Development of Method for the Measurement of Dermal Exposure on a Lifelike Cow Dummy to Assess the Risk of Using a Urease Inhibitor (Atmowell®) to Reduce NH3 Emissions in Cattle Farming

Up to 58% of NH3 emissions can be reduced through the use of the urease inhibitor Atmowell® in cattle farming. Automated manure scraper and drag hose systems should be used to apply urease inhibitors (UIs) to stable floors. Proof of safe use is also needed. A risk assessment of the urease inhibitor PPDA was conducted utilising estimated and calculated exposure data along with established and verified model calculation tools. Risk assessment models can be improved using measured dermal exposure data. The fluorescent dye pyranine and a Tyvek® collector were used to measure exposure. Tyvek® was attached to a lifelike cow dummy. Regarding the drag hose system, two worst-case scenarios were considered: over the cow and passing the cow. Regarding the robot application system, a 0 m frontal scenario was considered. The over the cow scenario exhibited the highest dermal exposure, with 1.5 mg of PPDA/cow per application run. The robot scenario exhibited the smallest amount, with 0.8 mg of PPDA/cow per application run. The risk of using PPDA was already excluded by model calculation tools in a risk assessment. Compared with the estimated and calculated dermal exposure values, the measured dermal exposure levels were reduced by a factor of two to six.

Determination of Selected Elements in Commercially Available Tattoo Inks of the Greek Market Using Atomic Absorption Spectrometry

In recent decades, tattooing has become a form of social and artistic expression. To apply a tattoo, the skin is marked by the internal injection of ink in the skin. Hence, it includes human health exposure to metals since the tattoo ink composition includes such elements. The present paper reports the determination and quantification of 8 elements (As, Cd, Co, Cr, Cu, Hg, Ni, Pb) in twenty tattoo ink colors available in the Greek market imported from the USA and China. The elemental content was carried out by atomic absorption spectrometry after microwave-assisted digestion. A comparison was carried out between the results of the present study and the maximum permitted concentrations as proposed in the ResAP and EPA guidelines, while the level of dermal exposure due to pigment application through ink injection was also estimated. All inks contained Cr, Cu, Ni, and Pb, while the content of As, Cd, and Co was below the detection limit in certain samples. Mercury was determined in three samples. Chromium, Cu, and Ni were present in the highest concentrations, while Cd and Hg contents were in general low. Most elements presented their maximum levels in the brown ink originating from USA.

Tiered human health risk assessment of antibacterial quaternary ammonium compounds (QACs) in dishwashing detergents

Quaternary ammonium compounds (QACs) are widely used in consumer products because of their unique antibacterial properties, and dishwashing detergents are a major source of exposure through oral, inhalation, and dermal routes. The three classes of QACs, including benzalkonium chloride (BAC), n-alkyldimethylethylbenzylammonium chloride (ADEBAC), and di-n-alkyldimethylammonium chloride (DDAC), in spray and non-spray types of dishwashing detergents were quantified by high-performance liquid chromatography-mass spectrometry. A tiered risk assessment approach was also considered. In the Tier 1 assessment, the mean and worst-case exposure were estimated to screen for rough exposure and risk levels. In the Tier 2 assessment, mean and upper-tail exposure levels were calculated based on the exposure parameters of Korean consumers using Monte Carlo simulation. QACs had a low frequency of detection of up to 20% in dishwashing detergents, and the contents of detected QACs varied depending on the individual samples. Based on the results of the Tier 1 assessment, BACs and DDACs posed potential health risks via inhalation and dermal routes. Tier 2 assessment suggested that the current level of oral and dermal exposure of Korean consumers to QACs in dishwashing detergents is unlikely to pose a health risk, even for upper-tail exposure groups. However, the present results suggest that spray-type DDACs may pose a health risk in the upper-tail inhalation exposure group, and further investigation is required to clarify this risk.

Age- and sex-specific dermal exposure of polycyclic aromatic hydrocarbons in the general population of a city in south China

This study assessed the dermal exposure of population to polycyclic aromatic hydrocarbons (PAHs) in a South China city. Skin wipe samples of the face, hand, forearm, and shank were collected from 120 volunteers (50% male and 50% female) belonging to different age groups (preschooler, thresholder, middle-aged, and elderly). Concentrations of PAHs in the skin wipe samples varied from 18 to 27000 ng/m2 in the order of face > hand > forearm > shank, regardless of age and gender. The PAH concentrations of bare skin locations were significantly higher in females than in males, while no significant differences were observed for clothing-covered skin locations between genders. The PAH concentrations for faces were significantly higher in the elderly compared to the other groups. The PAH composition was distinct between the four age groups. The dermal exposure levels of total PAHs and total BaP equivalent concentration (BaPeq) varied from 25.6 to 620 and 0.093–37.4 ng/kg body weight/d, respectively. The dermal exposure levels of total PAHs were significantly higher in females than in males in all age groups except for the middle-aged group. The hand-mouth exposure doses were significantly higher in the preschoolers than in the other age groups. The values of the carcinogenic risk caused by dermal PAH exposure were between 3.5 × 10−6 and 1.4 × 10−3 with 29% of the population (35/120) having risk values exceeding significant levels (1 × 10−4). The thresholder group exhibited the highest risk for PAH dermal exposure among all groups of the population. This study provides a comprehensive evaluation of the age- and gender-related risk of PAH through dermal exposure.

Health risk assessment of dermal exposure to Chlorpyrifos among children in agricultural areas in Sakon Nakhon Province, Thailand

Chlorpyrifos is a widely used agricultural insecticide. Chlorpyrifos exposure affects brain development and children’s overall health. The objective of this study was to assess the health risks from skin exposure to chlorpyrifos and to investigate the factors associated with chlorpyrifos exposure among children in agricultural areas. Residual chlorpyrifos samples were collected from the hands and feet of 130 children (aged 1–3) to analyze chlorpyrifos content using high-pressure liquid chromatography with a diode array detector. Chlorpyrifos residues were detected on the skin of 73.1% of the children tested. The health risk assessment of non-cancerous effects showed that children had dermal chlorpyrifos exposure at 1.46 × 10−5 mg/kg-day, and the hazard quotient (HQ) of child dermal chlorpyrifos exposure was 0.03, which is an acceptable level. The frequency of accompanying parents to pesticide-sprayed areas was significantly associated with dermal chlorpyrifos exposure levels in children (ORadjust =1.44, 95%CI =1.02–2.03). However, children in agricultural areas may be subject to additional health risks from exposure to other pesticides through respiration and ingestion. Therefore, they should not be allowed to accompany their parents to agricultural areas, and a program to prevent pesticides from affecting children in these areas should be developed.

Assessing Lung and Skin Cancer Risks for Steel and Iron Manufacturing Industry Workers Exposed to Polycyclic Aromatic Hydrocarbons

ABSTRACT Conducting both inhalatory and dermal samplings are crucial for chemicals, such as polycyclic aromatic hydrocarbons (PAHs), which are known with chronic dermal and inhalatory health effects. The present study is the first one set out for conducting both PAH inhalatory and dermal exposure assessments simultaneously for electric arc furnace (EAF) workers in an iron and steelmaking industry. The results were further used to assess the health risks posed on workers. Finally, risk-based control strategies were suggested. Three similar exposure groups (SEGs) of the melting, ladling, and casting were selected for conducting personal samplings. A total of 15 and 120 samples were collected for assessing workers’ inhalatory and dermal PAH exposures, respectively. Results show that the inhalatory gas-phase PAH exposure levels (2.17 × 104–1.52 × 105 ng m–3) were consistently higher than that of particle-phase (2.73 × 103–6.76 × 103 ng m–3) in all selected exposure groups. The mean inhalatory exposure concentrations of the melting and casting workers (2.84 × 104–3.32 × 104 ng m–3) were higher, but ladling workers (1.58 × 105 ng m–3) were lower, than the time-weighted average permissible exposure level (PEL-TWA) regulated in Taiwan (1.00 × 105 ng m–3). The estimated lifetime excessive lung cancer risks for the latter (2.09 × 10–3) were lower than that of the former (3.43 × 10-3–8.84 × 10–3), they were all higher than the significant risk (10–3) defined by the US Supreme Court. The mean whole-body total PAH dermal exposure levels were 2.84 × 105–7.45 × 105 ng day–1, and those body surfaces uncovered by clothes were found with higher exposure levels. Since the estimated lifetime excessive skin cancer risks (7.74 × 10–5–1.62 × 10–4) were lower than of the lung cancer risk, which indicates that the control of workers' inhalatory exposures is more important than that of dermal exposures. The installation of effective ventilation systems and the use of proper personal respiratory protection equipment are recommended for the abatement of risks posed on workers associated with PAH exposures.

Nickel: Intrinsic Skin Sensitization Potency and Relation to Prevalence of Contact Allergy.

Nickel remains the most commonly identified contact allergen. However, it has proven difficult to demonstrate significant skin-sensitizing activity for nickel in toxicology tests, which typically have indicated a weak skin sensitization potential. Information indicates that in vivo assays are not predictive of dermal sensitization hazard or potency for nickel due to a human-specific mechanistic route for nickel sensitization that animals lack. A similar rationale will apply to in vitro alternatives—although these currently have limited ability to determine intrinsic potency. Generally, in silico methods are not designed for metal allergens and cannot contribute to the analysis. For ethical reasons, human experimental work has been limited, with a single study suggesting moderate potency. Accordingly, it seems reasonable to conclude that the high frequency of contact allergy to nickel in humans is a function of both its intermediate potency coupled with a high level of dermal exposure, particularly to damaged/inflamed skin.

Experimental Assessment of Inhalation and Dermal Exposure to Chemicals During Industrial or Professional Activities in Relation to the Performance of ECETOC TRA.

For many work situations only insufficient exposure data are available to perform proper risk assessment. Because measuring worker exposure can be time consuming and resource intense, the availability of reliable exposure models is important when performing risk assessments. However, the development and improvement of exposure models are hampered by scarcity of sound exposure data as well as by lack of information on relevant exposure factors and conditions of exposure. This paper describes a study where inhalation and dermal exposure data were collected under defined conditions. Exposure scenarios examined included tasks that have not been investigated in previous validation studies. The results of these measurements were compared with ECETOC TRA model version 3.1 predictions. In this study, five exposure scenarios were selected, namely 'use in a closed batch process' (PROC 4), 'mixing or blending in a partly open batch process' (PROC 5), 'rolling' (PROC 10), 'immersion' (PROC 13), and 'stirring' (PROC 19). These PROCs stem from the descriptors that Registration, Evaluation and Authorization of Chemicals has established to depict the identified uses of chemical substances. These exposure scenarios were selected mainly because little or no data are available for these situations, or ECETOC TRA is likely to underestimate exposure for these situations. Experiments were performed by volunteers for the selected exposure scenarios, in which tasks were performed aiming to represent real workplace situations. In total 70 experiments were performed, during which 70 dermal exposure measurements (5 volunteers × 2 repeats × 7 scenarios) and 32 inhalation exposure measurements (4 volunteers × 2 repeats × 4 scenarios) were collected. Two formulations were used, namely pure Tinopal SWN powder (solid product, a fluorescent tracer) and 0.5% Tinopal SWN dissolved in 1,2-dichloroethane (1,2-DCE). DCE is considered a moderate volatile liquid. For exposure scenarios using the liquid formulation, both inhalation and dermal measurements were performed, while for exposure scenarios using the pure powder only dermal exposure measurements were performed. In addition, photographs were taken under ultraviolet light to qualitatively assess exposure patterns on hands and body. Volunteers repeatedly performed a selection of tasks under standardized conditions in a test chamber for each exposure scenario. Results show that ECETOC TRA overestimated dermal hand exposure for all PROCs included in the study, and was considered to be conservative. Additionally, ECETOC TRA overestimated inhalation exposure for closed and partially closed processes, but underestimated inhalation exposure for rolling and handling of immersed objects. Qualitative assessment of the hands and body showed mainly the hands were exposed for tasks involving closed and partially closed processes and when handling of immersed objects. Exposure to other body segments were also observed for rolling and stirring. In conclusion, this study gave insights into dermal and inhalation exposure levels during selected task scenarios, and showed that ECETOC TRA is conservative when dermal exposure is estimated. Inhalation exposure estimates for PROCs 10 and 13 tasks with the moderate volatility liquid were underestimated in this study. It may be therefore necessary to re-evaluate base model predictions for these scenarios when medium fugacity liquids are involved.

Persistence of indoor permethrin and estimation of dermal and non-dietary exposure.

Pesticides applied indoors may persist longer than they would in outdoor environments, making people more vulnerable to the risk of exposure. Permethrin is a pyrethroid insecticide used in agricultural, residential, and public health sites, and is commonly detected in indoor environments. The objectives of this study were to evaluate the persistence of permethrin indoors and to estimate the levels of possible dermal and non-dietary exposure to this insecticide. Permethrin was applied on aluminum foil and kept in a glass chamber and a test house for 112 days; its concentration was measured at application and after 28, 56, and 112 days. Permethrin persisted for the entire 112 days in concentrations equal to a maximum of 89.6% of the initial concentration. We observed low levels of human dermal and non-dietary exposure to permethrin.

Effect of spraying direction on the exposure to handlers with hand-pumped knapsack sprayer in maize field

Only less than one percent applied pesticides reach the target pest, the remainder spread out into the environment, effecting on workers, bystanders, consumers and so on. Handlers with manual knapsack sprayer are completely exposed to the pesticide spray plume when they deal with the pesticides. Those kinds of sprayer are widely used in developing countries, more than 75% of farmers using hand-pumped knapsack sprayer in China, yet rarely systematic studies had been focused on the typical applying scenario. The occupational exposure of pesticide is highly correlated with the pesticide spray plume flying time in the air in this scenario. Our study aimed to compare the estimated exposure level of handlers to chlorpyrifos sprayed at three spraying direction using a lever-operated knapsack in small farms in five agro-climatic zones of China. Experiments were performed by 24 farms in each province with three different crop heights (< 80 cm, spraying downward; 80–130 cm, spraying horizontal; and > 130 cm, spraying upward; eight farms for every direction) under typical field conditions. Each farmer covered a uniform area of 667 m2. The whole body dosimetry method and a personal air sampler were used to monitor the dermal and inhalation exposure. The estimated dermal exposure of the three spraying direction was 629, 1580, and 2140 mg/kg, respectively. The results showed that the total dermal exposure level increased with the spraying direction from downward to upward. Furthermore, appropriate cotton coveralls could reduce more than 90% of the total dermal exposure.

Potential operator dermal exposure during foliar indoor application: a comparison between knapsack, trolley sprayer and lance equipment

In accordance with the risk assessments required in the framework of Regulation (EC) no. 1107/2009, operator exposure must be determined taking into account the material and the conditions of use. However, the existing European Union harmonised predictive model (EFSA in EFSA J 12(10):3874, https://doi.org/10.2903/j.efsa.2014.3874 , 2014) has shortcomings, especially the lack of operator exposure data during applications in greenhouses. The aim of this study, performed in France, was to measure levels of operator dermal exposure in greenhouses where knapsack or trolley sprayers are used, and to evaluate the protection provided by dermal personal protective equipment under field conditions. The potential dermal exposure on the body and head excluding the hands, and on the hands ranged from 936 to 14,052 µg/day, and from 173 to 1762 µg/day, respectively. The transfer factors provided by the personal protective equipment (certified coverall and gloves) were low, 2.3% and 0.8% (75th percentile), respectively. When exposure levels measured during the spraying phase of the experimental exposure study were compared to those calculated using the new greenhouse model (Project Report, German Federal Institute for Risk Assessment (BfR), Berlin, http://www.bfr.bund.de/cm/350/joint-development-of-a-new-greenhouse-agricultural-operator-exposure-model-for-hand-held-application.pdf , Accessed 26 June 2018, 2015), the model prediction using the dense culture scenario for potential body and head exposures fits well with the levels of exposure measured in the experimental study. The results of this experimental greenhouse exposure study could be used to increase the robustness of operator exposure estimates provided by the Greenhouse Agricultural Operator Exposure Model (Project report-BfR 2015) in the context of pesticide applications in greenhouses.

Exposure Neuroepidemiology Study among Occupational Groups with High Exposure to Aviation Emissions

Aviation industry personnel working at the airports in Pakistan are confronted with neurasthenic and physical problems mainly because of unprecedented exposure to jet fuels and also there is no proper health monitoring services are extended to them. We aimed to assess dermal exposure of workforce at airports to jet propellant (JP) fuel (e.g. JP4, JP5, and JP8) which contains a complex of mixture of Polycyclic Aromatic Hydrocarbons (PAHs). To document the extent of acute toxic exposure levels, protective strategies, working hours and job nature were used as predictors. Among aviation workforce members, who work for more than six hours per day, we took both skin pad and urine samples to measure dermal exposure by PAH and subsequent secretion through body. To detect biological marker for dermal exposure urinary pyrene metabolite was quantified. The results show that workers at the airport have high jet fuel dermal exposure. However, the mean pyrene exposure levels were reduced to 33% when they use masks during work. Urinary 1-hydroxyprene was detected as the biological measure to quantify the internal exposure to PAHs present in JP fuels whose concentration was relatively low (range 35 and 174 nmol) when compared to dermal exposure levels. Workers exposed to 6 hour per day or more had significantly high prevalence of physical disorders (OR&amp;#61;3.17, 95% CI&amp;#61;1.33&amp;#8211;7.12). Neurasthenic symptoms (e.g. energy loss, fatigue, fainting, twitching, sleeplessness, irritability, body aches) were found in 58% of the subjects and were associated with years of involvement in job. In aviation industry, working at the airport for ten years or more attributed substantial development of neurasthenic effects (OR&amp;#61;3.85, 95% CI&amp;#61;1.71&amp;#8211;8.84). Results of multiple regression analysis revealed mass balance between dermal pyrene dose and 1-hydroxyprene excretion that confirmed the relevance of the dermal exposure route.

Literature review: dermal monitoring data for pesticide exposure assessment of farm workers

ABSTRACTObjective: To conduct a literature review to determine the types of information that existing dermal pesticide monitoring data could provide for future pesticide exposure assessment in occupational epidemiology.Methods: A systematic literature search was performed on eight online databases. Two screening phases with predetermined criteria identified the qualifying literature. Standard information and dermal pesticide monitoring data were recorded and summarized from each qualifying study to assess its usefulness for future pesticide exposure assessment.Results: A total of 31 farm studies qualified for review; task information was used to standardize all farm job(s) evaluated into 5 job groups: operators, applicators, mixer-loaders, field workers, and flaggers. When attempting to compare dermal exposure levels between studies, two types of variation were identified: (1) variation in study focus and reporting and 2) variation in exposure levels. The former variation type prevented exposure level comparisons between studies. Within studies, exposure levels were compared across body parts to identify that which had the highest measured exposure and to determine if results were similar in other studies that evaluated the same farm job. Using studies that measured exposure for multiple farm jobs, within study comparisons of total body exposure were performed to evaluate work factors.Conclusion: Future dermal pesticide exposure monitoring studies should standardize reporting procedures, as suggested in this review, to allow for more extensive dermal data comparisons. Body parts with highest measured levels of dermal exposure were identified by farm job, along with work factors to be further investigated as potential dermal pesticide exposure determinants for farm workers.

Validation of the dermal exposure model in ECETOC TRA.

The ECETOC TRA model (presently version 3.1) is often used to estimate worker inhalation and dermal exposure in regulatory risk assessment. The dermal model in ECETOC TRA has not yet been validated by comparison with independent measured exposure levels. This was the goal of the present study. Measured exposure levels and relevant contextual information were gathered via literature search, websites of relevant occupational health institutes and direct requests for data to industry. Exposure data were clustered in so-called exposure cases, which are sets of data from one data source that are expected to have the same values for input parameters in the ECETOC TRA dermal exposure model. For each exposure case, the 75th percentile of measured values was calculated, because the model intends to estimate these values. The input values for the parameters in ECETOC TRA were assigned by an expert elicitation and consensus building process, based on descriptions of relevant contextual information.From more than 35 data sources, 106 useful exposure cases were derived, that were used for direct comparison with the model estimates. The exposure cases covered a large part of the ECETOC TRA dermal exposure model. The model explained 37% of the variance in the 75th percentiles of measured values. In around 80% of the exposure cases, the model estimate was higher than the 75th percentile of measured values. In the remaining exposure cases, the model estimate may not be sufficiently conservative.The model was shown to have a clear bias towards (severe) overestimation of dermal exposure at low measured exposure values, while all cases of apparent underestimation by the ECETOC TRA dermal exposure model occurred at high measured exposure values. This can be partly explained by a built-in bias in the effect of concentration of substance in product used, duration of exposure and the use of protective gloves in the model. The effect of protective gloves was calculated to be on average a factor of 34 in this data set, while factors of five to ten were used in the model estimations. There was also an effect of the sampling method in the measured data on the exposure levels. Exposure cases where sampling was done via an interception method, such as gloves, on average showed a factor of six higher 75th percentiles of measured values than exposure cases where sampling was done via a removal method, such as hand washing. This may partly be responsible for the apparent underestimation of dermal exposure by the model at high exposure values. However, there also appeared to be a relation between expected exposure level (as indicated by the model estimate) and the choice of sampling method.In this study, solid substances used in liquid products were treated as liquids with negligible volatility. The results indicate that the ECETOC TRA dermal exposure model performs equally well for these substances as for liquids. There were suggestions of a difference in performance of the model between solids and liquids.For several parts of the ECETOC TRA dermal model, no or hardly any measured dermal exposure data were available. Therefore, gathering of more dermal exposure levels is recommended, specifically for situations not yet sufficiently covered in the present data set.

Dermal exposure of applicators to chlorpyrifos on rice farms in Ghana

Studies evaluating dermal exposure to pesticides among applicators in tropical countries have largely been conducted using the patch dosimetry and hand wiping/washing techniques. This study used the more accurate whole-body dosimetry technique to evaluate dermal exposure to chlorpyrifos among applicators on rice farms in Ghana. The exposure levels were plotted as Cumulative Probability Distribution (CPD). Total Dermal Exposure (TDE) of chlorpyrifos among the median exposed and the 5% highly exposed groups during a spray event were 24 mg and 48 mg, respectively. When these were converted as a percentage of the quantity of active ingredient applied (Unit Exposure, UE), UE values of 0.03% and 0.06% were found among the median exposed and the 5% highly exposed groups, respectively. Overall, the hands were the most contaminated anatomical regions of the applicators, both in terms of proportion of TDE (39%) and skin loading (13 μg/cm2). Also, the lower anatomical region was more contaminated (82% of TDE) compared to the upper anatomical region (18% of TDE). The levels of chlorpyrifos TDE among the applicators were found to be influenced by the quantity of insecticide applied and the height of the crops sprayed (p < 0.05). The pesticide UE data of the present study can be used to estimate the levels of dermal exposure under similar pesticide use scenarios among applicators. The findings of the present study suggest that protecting the hands and the lower anatomical regions with appropriate PPE may significantly reduce exposure among applicators.

Operator dermal exposure and individual protection provided by personal protective equipment during application using a backpack sprayer in vineyards

According to Regulation (EC) No 1107/2009, the safety of the operator concerning plant protection products (PPP) must be evaluated. The levels of operator exposure with use of certified personal protective equipment can be estimated using a model or experimental exposure data. However, the existing models have shortcomings, especially the lack of operator exposure data during upward applications using a backpack sprayer. The aim of this study was to monitor the dermal exposure of operators using backpack motorised mist-blower power sprayers for application of fungicides in vineyards. The measured actual dermal exposure levels ranged from 49.3 mg/kg a.s. (active substance) applied (75th percentile) to 89.2 mg/kg a.s. applied (95th percentile), and were lower than those estimated with the European Food Safety Authority model (5–2 %, respectively). The transfer factors provided by the personal protective equipment (coverall and gloves) were low, 1.7 and 2.4 % (75th percentile) and 5.1 and 8.6 % (95th percentile) respectively.

Characterizing Flame Retardant Applications and Potential Human Exposure in Backpacking Tents.

Flame retardant (FR) chemicals are applied to products to meet flammability standards; however, exposure to some additive FRs has been shown to be associated with adverse health effects. Previous research on FR exposure has primarily focused on chemicals applied to furniture and electronics; however, camping tents sold in the United States, which often meet flammability standard CPAI-84, remain largely unstudied in regards to their chemical treatments. In this study, FRs from five brands of CPAI-84-compliant, two-person backpacking tents were measured and potential exposure was assessed. Dermal and inhalation exposure levels were assessed by collecting hand wipes from 20 volunteers before and after tent setup and by using active air samplers placed inside assembled tents, respectively. Organophosphate flame retardants (OPFRs) were the most commonly detected FR in the tent materials and included triphenyl phosphate (TPHP), tris(1,3-dichloro-2-propyl)phosphate (TDCIPP) and tris(2-chloroethyl)phosphate (TCEP). Levels of OPFRS measured on hand wipes were significantly higher post-tent setup compared to pre setup, and in the case of TDCIPP, levels were 29 times higher post setup. OPFRs were also detected at measurable concentrations in the air inside of treated tents. Significant, positive correlations were found between FR levels in treated textiles and measures of dermal and inhalation exposure. These results demonstrate that dermal exposure to FRs occurs from handling camping tents and that inhalation exposure will likely occur while inside a tent.

Exposure monitoring and risk assessment of biphenyl in the workplace.

This study was performed to assess exposure to and the risk caused by biphenyl in the workplace. Biphenyl is widely used as a heat transfer medium and as an emulsifier and polish in industry. Vapor or high levels of dust inhalation and dermal exposure to biphenyl can cause eye inflammation, irritation of respiratory organs, and permanent lesions in the liver and nervous system. In this study, the workplace environment concentrations were assessed as central tendency exposure and reasonable maximum exposure and were shown to be 0.03 and 0.12 mg/m3, respectively. In addition, the carcinogenic risk of biphenyl as determined by risk assessment was 0.14 × 10−4 (central tendency exposure) and 0.56 × 10−4 (reasonable maximum exposure), which is below the acceptable risk value of 1.0 × 10−4. Furthermore, the central tendency exposure and reasonable maximum exposure hazard quotients were 0.01 and 0.06 for oral toxicity, 0.05 and 0.23 for inhalation toxicity, and 0.08 and 0.39 for reproduction toxicity, respectively, which are all lower than the acceptable hazard quotient of 1.0. Therefore, exposure to biphenyl was found to be safe in current workplace environments. Because occupational exposure limits are based on socioeconomic assessment, they are generally higher than true values seen in toxicity experiments. Based on the results of exposure monitoring of biphenyl, the current occupational exposure limits in Korea could be reviewed.