Squalene Depletion in Skin Following Human Exposure to Ozone under Controlled Chamber Conditions.

A major component of human skin oil is squalene, a highly unsaturated hydrocarbon that protects the skin from atmospheric oxidants. Skin oil, and thus squalene, is continuously replenished on the skin surface. Squalene is also quickly consumed through reactions with ozone and other oxidants. This study examined the extent of squalene depletion in the skin oils of the forearm of human volunteers after exposure to ozone in a climate chamber. Temperature, relative humidity (RH), skin coverage by clothing, and participants' age were varied in a controlled manner. Concentrations of squalene were determined in skin wipe samples collected before and after ozone exposure. Exposures to ozone resulted in statistically significant decreases in post-exposure squalene concentrations compared to pre-exposure squalene concentrations in the skin wipes when squalene concentrations were normalized by concentrations of co-occurring cholesterol but not by co-occurring pyroglutamic acid (PGA). The rate of squalene loss due to ozonolysis was lower than its replenishment on the skin surface. Within the ranges examined, temperature and RH did not significantly affect the difference between normalized squalene levels in post-samples versus pre-samples. Although not statistically significant, skin coverage and age of the volunteers (three young adults, three seniors, and three teenagers) did appear to impact squalene depletion on the skin surfaces.

New commercial wipes inhibit the dispersion and adhesion of Staphylococcus aureus and Pseudomonas aeruginosa biofilms.

AIM: Bacterial biofilms can form on surfaces in hospitals, clinics, farms, and food processing plants, representing a possible source of infections and cross-contamination. This study investigates the effectiveness of new commercial wipes against Staphylococcus aureus and Pseudomonas aeruginosa biofilms (early attachment and formed biofilms), assessing LH SALVIETTE wipes (Lombarda H S.r.l.) potential for controlling biofilm formation. METHODS AND RESULTS: The wipes efficacy was studied against the early attachment phase and formed biofilm of S. aureus ATCC 6538 and P. aeruginosa ATCC 15442 on a polyvinyl chloride (PVC) surface, following a modified standard test EN 16615:2015, measuring Log10 reduction and cell viability using live/dead staining. It was also evaluated the wipes anti-adhesive activity over time (3 h, 2 4h), calculating CFU.mL-1 reduction. Data were analyzed using t-student test. The wipes significantly reduced both early phase and formed S. aureus biofilm, preventing dispersion on PVC surfaces. Live/dead imaging showed bacterial cluster disaggregation and killing action. The bacterial adhesive capability decreased after short-time treatment (3 h) with the wipes compared to 24 h. CONCLUSIONS: Results demonstrated decreased bacterial count on PVC surface both for early attachment phase and formed biofilms, also preventing the bacterial biofilm dispersion.

The effectiveness of a school-based protocol for environmental cleaning and disinfection during a pandemic: a randomized controlled pilot study.

BACKGROUND: Since no specific environmental cleaning instructions and methods have been developed for schools to tackle pandemics, and cleaning methods, this study aims to investigate the feasibility of a new effective school cleaning protocol in reducing the environmental contamination in kindergarten and primary school settings. METHODS: This study implemented a cluster randomized controlled trial with three-arms, namely two intervention arms - groups A and B, and one control arm - group C. The first intervention arm included the cleaning staff who would participate in an educational workshop and be equipped with disposable wipes, while the second arm, group B, participated in the educational workshop only. The third arm, group C, received no treatments. RESULTS: 1080 sample points were collected from pre-determined sites in the study within the 6 schools. At the 2-week follow-up post-intervention assessment, all sites were found to be clean for group A that used disposable wipes, while group B, without disposable wipes, were found to have left more sites contaminated. Staphylococcus aureus was found in the sites cleaned by group C. CONCLUSION: Based on the findings in this pilot study, a further study at a larger scale focusing on the education program with enhancement and use of the cleaning protocol can be conducted to train cleaning staff for effective environmental cleaning in a school setting.

Exposure and Risk Assessment of Korean Firefighters to PBDEs and PAHs via Fire Vehicle Dust and Personal Protective Equipment.

In this study, the levels of polycyclic aromatic hydrocarbons (PAHs) and polybrominated diphenyl ethers (PBDEs) were characterized in firefighters' personal protective equipment (PPE) (i.e., jackets, pants, hoods, and gloves) and vehicle dust wipe samples to assess the exposure and potential risk of firefighters to these combustion-related toxic pollutants. The mean levels of ∑PBDEs in the fire vehicle dust samples (778 and 449 pg/cm2 for pump trucks and command cars, respectively) were significantly higher than those in the private vehicles (31.2 pg/cm2) (Kruskal-Wallis test, p < 0.05), which was similar to the ∑PAH levels (521, 185, and 46.8 pg/cm2 for pump trucks, command cars, and private vehicles, respectively). In the case of firefighters' PPE, the levels of ∑PBDEs and ∑PAHs in used jackets and pants were found to be, respectively, 70- to 2242-folds and 11- to 265-folds higher than those in their unused counterparts. Biomass/petroleum combustion was found to be the main source of PAH contamination in fire vehicle dust and used PPE in the present study. Both carcinogenic and noncarcinogenic risks via vehicle dust ingestion and dermal absorption from wearing of PPE were within permissible limits, although the relative risk evaluation showed that PAH/PBDE absorption via wearing of PPE could pose a higher likelihood of carcinogenic and noncarcinogenic risks than the ingestion of pollutants via fire vehicle dust, warranting the need for appropriate management of firefighters' personal protective ensembles.

Quantifying exposure to chlorhexidine from decontamination of peripheral intravenous injection ports.

BACKGROUND: Annually, almost 2 billion peripheral intravenous cannulas (PIVCs) are placed worldwide. In response to concerns of infectious complications, chlorhexidine is increasingly utilised for maintenance decontamination of PIVC injection ports. Concomitantly, the allergenic potential of chlorhexidine exposures has been highlighted by several case reports, implicating it as a trigger when used for this seemingly innocuous process. Given how widespread this application is, elucidating potential chlorhexidine exposure is needed to gauge its risks and benefits. OBJECTIVE: To examine and quantify if chlorhexidine is entrained when used for PIVC injection port cleaning. METHODS: Twenty benchtop PIVC set-ups were cleaned with 2% chlorhexidine and 70% alcohol wipes, following three different pragmatic protocols. Each set-up was injected with 10 ml ultrapure water, and samples tested by liquid chromatography-electrospray tandem mass spectrometry for entrained chlorhexidine. RESULTS: Chlorhexidine was detected in every sample. Mean concentrations and standard deviations from each protocol were 41.47 ppb (4.08), 54.76 ppb (17.46), and 65.84 ppb (7.01). One-way ANOVA indicated a statistical difference between at least two groups (df = 2, F = 24.11, p < .00001), with Tukey's testing verifying significantly different mean concentrations between all groups (p < .01). CONCLUSIONS: Using 2% chlorhexidine and 70% alcohol swabs to decontaminate PIVC injection ports resulted in consistent entrainment of chlorhexidine, with varying amounts correlated to how it was applied. These results validate case reports attributing anaphylactic/allergic reactions to suspected intravenous chlorhexidine entrainment and should factor into future risk-benefit assessments for its use in PIVC maintenance antisepsis policies and protocols.

Quantification of Methylisothiazolinone and Methylchloroisothiazolinone Preservatives by High-Performance Liquid Chromatography.

Isothiazolinone preservatives (methylisothiazolinone (MIT) and methylchloroisothiazolinone (CMIT) are commonly used in cosmetics, industrial and household products. However, these isothiazolinone derivatives are known to cause allergic contact dermatitis. Hence, a sensitive, accurate, and reliable method for the detection of these compounds is thus warranted. The study aims to analyze concentrations of MIT and CMIT by high performance liquid chromatography. The analytical method used for quantification of MIT and CMIT in cosmetic products (leave-on-baby wet wipes) complies with the validation acceptance criteria (international standards ISO 5725, EU25 European Union for cosmetic regulations). MIT and CMIT were extracted and analyzed in leave-on baby wet-wipes collected from different stores in Riyadh city. Extraction was performed by ultrasonication of the samples, solid-phase extraction, and liquid-liquid extraction. Ten (10) µL of the sample was injected into the HPLC system and samples were analyzed with a mixture of acetic acid and methanol (80:20 v/v) in an isocratic mode. The flow rate was maintained at 1 mL/min. UV detection was performed at 274 nm. The results demonstrated recoveries between 90 and 106%, measurement uncertainty of C +/- 0.4% for methylisothiazolinone and C +/- 0.03% for methylchloroisothiazolinone, repeatability limit (r = 0.2%) and intermediate precision limit; R = 2% and R2 of 0.9996.

Washable Antimicrobial Wipes Fabricated from a Blend of Nanocomposite Raw Cotton Fiber.

In this study, a simple and effective way to produce washable antimicrobial wipes was developed based on the unique ability of raw cotton fiber to produce silver nanoparticles. A nanocomposite substructure of silver nanoparticles (25 ± 3 nm) was generated in raw cotton fiber without reducing and stabilizing agents. This nanocomposite raw cotton fiber (2100 ± 58 mg/kg in the concentration of silver) was blended in the fabrication of nonwoven wipes. Blending small amounts in the wipes-0.5% for antimicrobial properties and 1% for wipe efficacy-reduced the viability of S. aureus and P. aeruginosa by 99.9%. The wipes, fabricated from a blend of 2% nanocomposite raw cotton fiber, maintained their antibacterial activities after 30 simulated laundering cycles. The washed wipes exhibited bacterial reductions greater than 98% for both Gram-positive and Gram-negative bacteria.

Minimum wiping pressure and number of wipes that can remove dirt during bed baths using disposable towels: a multi-study approach.

BACKGROUND: Friction irritation by wiping increases the risk of skin problems. In bed baths with cotton towels, wiping three times with weak pressure (10-20 mmHg ≈ 1333-2666 Pa) can remove dirt while maintaining skin barrier function. However, few studies have examined the appropriate frictional irritation with disposable towels. This study aimed to analyse the wiping pressure and number of wipes currently applied by nurses when using disposable towels during bed baths and propose the minimum values for removing dirt from the skin. METHODS: This multi-study approach consisted of cross-sectional and crossover design components. In Study 1, 101 nurses in two hospitals were observed by recording the wiping pressure and number of wipes when using both disposable (nonwoven) and cotton (woven) towels. Wiping pressure and number of wipes by towel materials were analysed using a linear mixed model. In Study 2, 50 adults received oily and aqueous dirt on their forearms, which were wiped six-times with disposable towels, applying randomly assigned pressure categories. We used colour image analysis and a linear mixed model to estimate the dirt removal rate for each combination of wiping pressure and number of wipes. RESULTS: Study 1 showed that although wiping pressure did not differ by towel material, the number of wipes was significantly higher for disposable wipes than cotton wipes. Approximately 5% of nurses applied strong wiping pressure or wiped too often. In Study 2, wiping three times with disposable towels at least 5-10 mmHg achieved dirt removal rates of ≥80%. CONCLUSIONS: Some nurses excessively wiped using disposable towels, which might cause skin problems. However, excessive wiping is not required to adequately remove dirt, regardless of the towel material used in various clinical situations. We recommend wiping at 10-20 mmHg of pressure (just like stroking gently) at least three times to improve the quality of bed baths. These findings highlight the need to develop skin-friendly bed bath educational programmes, particularly using appropriate frictional irritation to reduce the risk of skin problems.

Estimating the proportion of bioaccessible lead (BaPb) in household dust wipe samples: a comparison of IVBA and PBET methods.

Established methods for using standardized dust wipes to collect and measure total lead in household dust are readily available but the use of dust wipes to measure bioaccessible lead (BaPb) is less clear. This study compared two in vitro methods for estimating the proportion of BaPb in dust collected into dust wipes including the US-EPA's in-vitro bioaccessible assay (IVBA) method at two pH (1.5 and 2.5) values; and the physiologically based extraction test (PBET 2.5 pH). Two types of simulated household dust samples (Pb-soil contaminated and Pb-paint contaminated) each with three Pb concentrations were created. Equal amounts of simulated dust were applied to a smooth surface and collected following the standard EPA dust wipe protocol and were analyzed for BaPb and total Pb (ASTM-E1644-17, ICP-OES). Estimated BaPb levels differed significantly by the method of extraction. Mean percent BaPb were IVBA pH 1.5, > 90% (Pb-paint) and 59-63% (Pb-soil); IVBA pH 2.5 78-86% (Pb-paint) and 45-50% (Pb-soil); PBET pH 2.5 56 to 61% (Pb-paint) and 41-50% Pb-soil). Particularly for lead-paint contaminated dust, PBET showed significantly greater discrimination as suggested by the broader range of BaPb values and closer approximation to total lead concentrations in simulated household dust samples.

Electronic-Waste-Driven Pollution of Liquid Crystal Monomers: Environmental Occurrence and Human Exposure in Recycling Industrial Parks.

Liquid crystal monomers (LCMs) in liquid crystal displays (LCDs) may be released into the environment, especially in electronic waste (e-waste) recycling industrial parks with a high pollution risk. However, little has been known about the environmental release and human exposure to LCMs until now. Herein, a total of 45 LCMs were detected in LCDs of commonly used smartphones and computers by high-resolution mass spectrometry with suspect screening analysis. Fluorinated biphenyls and their analogs were the dominant LCMs. Based on available standards of the screening results and previous studies, 55 LCMs were quantified in samples from an e-waste recycling industrial park in Central China. The LCMs were frequently detected in outdoor dust (n = 43), workshop #1 indoor dust (n = 53), and hand (n = 43) and forehead wipes (n = 43), with median concentrations of 6950 ng/g, 67,400 ng/g, 46,100 ng/m2, and 62,100 ng/m2, respectively. The median estimated daily intake values of the LCMs via dust ingestion and dermal absorption were 48.3 and 16.5 ng/kg body weight/day, respectively, indicating a high occupational exposure risk of these compounds. In addition, 16 LCMs were detected in the serum of eight elderly people (≥60 years old) with over 5 years of experience in e-waste dismantling operations, resulting in a total concentration range of 3.9-26.3 ng/mL.

Household use of green and homemade cleaning products, wipe application mode, and asthma among French adults from the CONSTANCES cohort.

While exposure to irritant and sprayed cleaning products at home is known to have a harmful role in asthma, the potential health effect of other categories or forms has not been investigated. We studied the associations of household use of cleaning products, including green, homemade products, and disinfecting wipes, with asthma based on data from the large French population-based CONSTANCES cohort. Participants completed standardized questionnaires on respiratory health and household use of cleaning products. Cross-sectional associations of cleaning products with current asthma, adjusted for gender, age, smoking status, BMI, and educational level, were evaluated by logistic regressions. Analyses were conducted in 41 570 participants (mean age: 47 years, 56% women, weekly use of the six specific products/forms studied varied from 11% to 37%). Weekly use of irritants (OR = 1.23 [1.13-1.35]), scented (OR = 1.15 [1.06-1.26]), green (OR = 1.09 [1.00-1.20]), and homemade products (OR = 1.19 [1.06-1.34]), as well as sprays (OR = 1.18 [1.08-1.29]), disinfecting wipes (OR = 1.21 [1.09-1.34]) were significantly associated with asthma, with significant trends according to the frequency of use. When they were not co-used with irritants/sprays, associations were reduced and persisted only for disinfecting wipes. Weekly use of disinfecting wipes at home was associated with current asthma, but fewer risks were observed for the use of green and homemade products.

Pesticide residues on children's hands, home indoor surfaces, and drinking water among conventional and organic farmers in Thailand.

This study measured pesticide levels on children's hands, home indoor surfaces, and drinking water among Thai conventional and organic farm families in three provinces. Farm families in Nakhonsawan and Phitsanulok provinces were the conventional farmers and those in Yasothon province were the organic farmers. Samples were collected in the dry and wet seasons over 2 years (2017 and 2018). All samples were analyzed for organophosphates (OPs), carbamate, pyrethroid, triazines, glyphosate, and aminomethylphosphonic acid (AMPA). On children's hands, the highest concentrations for the 2 palmar surfaces were found for cypermethrin (7.46 µg) and fipronil (2.88 µg). On home surfaces of approximately 1000 cm2, the highest concentrations were found for cypermethrin (27.94 µg) and fipronil 49.76 µg)/1000 cm2. For the conventional farmers, the most common pesticides on children's hand wipes were cypermethrin and fipronil, which are used as in-home pesticides as well as agricultural pesticides. However, home surface wipes showed other pesticides associated with agriculture were presented in the home during the seasons when they were used, suggesting spray drift or carry home sources for these pesticides. During the wet season, pesticides were found in the drinking water of all provinces. Most common were fenitrothion, profenofos, fenthion, atrazine, and AMPA. Profenofos was found at levels above the health guidelines. During 2017, there was extensive flooding in Thailand which may have contributed to the drinking water contamination, even though most farmers report using tap water or bottled drinking water. Future work is needed to assess the risk of all sources of pesticide exposures in children and to repeat the drinking water pesticide contamination analysis.

Bed bath with soap and water or disposable wet wipes: Patients' experiences and preferences.

AIMS AND OBJECTIVES: To gain an in-depth understanding of patients' preferences regarding two bed bath methods: soap and water and disposable wet wipes. BACKGROUND: Bed baths allow hospitalised, bedridden patients to stay clean and fresh. They serve a number of purposes: health promotion, social propriety and pure pleasure. Traditionally, soap and water have been used for personal hygiene, but in recent years soap and water have increasingly been replaced by the use of disposable wet wipes. DESIGN: A qualitative study with a hermeneutical-phenomenological approach was chosen to explore and understand patients' experiences of bed bath methods. METHODS: Semi-structured, individual, in-depth interviews with 16 bedridden patients from three wards were conducted. The software program nvivo was used to structure the transcribed interviews and assist in the initial data analysis. The data were analysed and interpreted within a phenomenological-hermeneutical framework. COREQ guidelines were used in the preparation of this paper (See Supporting information Appendix S1). RESULTS: Four overall themes were identified: "Creating a sense of cleanliness," "Preferences and concerns in different situations," "Cleanliness of hands and face" and "Clinical decision-making about bed bath method." CONCLUSIONS: Overall, patients' bed bath preference was for soap and water, but disposable wet wipes were considered a convenient alternative and preferred in certain circumstances, for example, when a patient had pain or diarrhoea. Shared decision-making regarding bed bath method is recommended. Hands and face had specific requirements. RELEVANCE TO CLINICAL PRACTICE: Nursing staff should be aware that bedridden patients have varying preferences, and it is important to incorporate the patients' preferences in the development of standards, health policies and clinical guidelines for bed bath practices.

Lead exposure in young children over a 5-year period from urban environments using alternative exposure measures with the US EPA IEUBK model - A trial.

The US Environmental Protection Agency (EPA) Integrated Exposure Uptake Biokinetic (IEUBK) model has been widely used to predict blood lead (PbB) levels in children especially around industrial sites. Exposure variables have strongly focussed on the major contribution of lead (Pb) in soil and interior dust to total intake and, in many studies, site-specific data for air, water, diet and measured PbB were not available. We have applied the IEUBK model to a comprehensive data set, including measured PbB, for 108 children monitored over a 5-year period in Sydney, New South Wales, Australia. To use this data set, we have substituted available data (with or without modification) for standard inputs as needed. For example, as an alternative measure for soil Pb concentration (µg/g), we have substituted exterior dust sweepings Pb concentration (µg/g). As alternative measures for interior dust Pb concentration (µg/g) we have used 1) 30-day cumulative petri dish deposition data (PDD) (as µg Pb/m2/30days), or 2) hand wipe data (as µg Pb/hand). For comparison, simulations were also undertaken with estimates of dust Pb concentration derived from a prior regression of dust Pb concentration (µg/g) on dust Pb loading (µg/ft2) as concentration is the unit specified for the Model. Simulations for each subject using observed data aggregated over the 5-year interval of the study, the most usual application of the IEUBK model, showed using Wilcoxon tests that there was a significant difference between the observed values and the values predicted by the Model containing soil with hand wipes (p < 0.001), and soil and PDD (p = 0.026) but not those for the other two sets of predictors, based on sweepings and PDD or sweepings and wipes. Overall, simulations of the Model using alternative exposure measures of petri dish dust (and possibly hand wipes) instead of vacuum cleaner dust and dust sweepings instead of soil provide predicted PbB which are generally consistent with each other and observed values. The predicted geometric mean PbBs were 2.17 ( ± 1.24) µg/dL for soil with PDD, 1.95 ( ± 1.17) µg/dL for soil with hand wipes, 2.36 ( ± 1.75) µg/dL for sweepings with PDD, and 2.15 ( ± 1.69) for sweepings with hand wipes. These results are in good agreement with the observed geometric mean PbB of 2.46 ( ± 0.99) µg/dL. In contrast to all other IEUBK model studies to our knowledge, we have stratified the data over the age ranges from 1 to 5 years. The median of the predicted values was lower than that for the observed values for every combination of age and set of measures; in some cases, the difference was statistically significant. The differences between observed and predicted PbB tended to be greatest for the soil plus wipes measure and for the oldest age group. Use of 'default dust' values calculated from the site-specific soil values, a common application of the IEUBK model, results in predicted PbB about 22% (range 0 to 52%) higher than those from soil with PDD data sets. Geometric mean contributions estimated from the Model to total Pb intake for a child aged 1-2 years was 0.09% for air, 42% for diet, 5.3% for water and 42% for soil and dust. Our results indicate that it is feasible to use alternative measures of soil and dust exposure to provide reliable predictions of PbB in urban environments.

Assessment of occupational exposure to airborne chlorine dioxide of healthcare workers using impregnated wipes during high-level disinfection of non-lumened flexible nasoendoscopes.

Routine flexible nasoendoscopy in otolaryngology clinics is well established, the rate-limiting step of which being the speed of the nasoendoscopes reprocessing method used. Non-lumened flexible nasoendoscopes are expensive, heat-sensitive, delicate instruments that cannot be sterilized in an autoclave but must be disinfected by means of high level disinfection (HLD). In one of the public hospitals in Singapore, the method of disinfection was recently changed to the use of commercial impregnated wipes which generates less than 1% chlorine dioxide upon activation. An exposure assessment was performed to assess the potential exposure of healthcare workers (HCWs) to airborne chlorine dioxide during nasoendoscope disinfection. A total of 14 long-term personal samples, four short-term personal samples and 16 long-term area samples were collected over 8 days in midget impingers containing 0.02% potassium iodide in sodium carbonate/sodium bicarbonate buffer during the nasoendoscope disinfection. The samples were then analyzed by ion-chromatograph. The chlorine dioxide concentrations and upper confidence limit at 95% confidence level (UCL95%) for personal and area samples collected were all below the occupational exposure limits (OEL) for chlorine dioxide (Singapore Workplace Safety and Health PELs, ACGIH TLVs, U.S. OSHA PELs). The study presented evidence that the exposure of HCWs to chlorine dioxide during high-level disinfection of flexible nasoendoscopes were deemed insignificant.

Brominated and organophosphorus flame retardants in body wipes and house dust, and an estimation of house dust hand-loadings in Dutch toddlers.

Children generally have higher Flame Retardant (FR) concentrations in serum compared to other age groups. Toddler behavior enhances direct contact with house dust since their frequent presence proximate to the floor, and their mouthing behavior. This study aimed to thoroughly investigate FR levels in body wipes of toddlers 8-18 months old) and in indoor dust using a noninvasive sampling technique. In this cross-sectional study, body wipes from hands, mouth and back, and indoor household dust samples were collected in twenty-one families and analyzed for one brominated- and seven organophosphorus FRs (polybrominated diphenyl ether 209 (BDE209), tris(2-chloroisopropyl) phosphate (TCIPP), tris(chloroethyl) phosphate (TCEP), tris(1,3-dichloroisopropyl) phosphate (TDCIPP), tris(phenyl) phosphate (TPHP), tris(methylphenyl) phosphate (TMPP), resorcinol bis(diphenyl phosphate) and bisphenol A bis(diphenyl phosphate)). Accelerated solvent extraction was used for extraction and the extract was measured with liquid chromatography combined with mass spectrometry. Non-parametric correlation analyses were performed to assess associations. All FRs were detected in body- and indoor dust samples (median range: 1.0ng/hand wipe (BDE209) to 65ng/hand wipe (TCIPP)) and were mostly correlated with each other. We estimated that approximately 260mg dust (range 50-880mg) accumulated on toddler's hands per day. Hand-to-mouth frequency was negatively associated with FR levels in wipes (τ = -0.38, p = 0.04). With increasing age FR concentrations (BDE209, TCEP, TDCIPP, TPHP and TMPP) on hands decreased significantly (p = 0.01-0.03). Girls had significantly less FRs (TCEP, TCIPP, TPHP and TMPP) on the hands (p = 0.01-0.03) than boys. This is to the best of the authors' knowledge the first study in Europe that measured brominated- as well as organophosphorus FRs in several types of body wipes from toddlers and that estimated the amount of house dust that accumulates on toddler's hands.

Lessons learned from surface wipe sampling for lead in three workplaces.

Surface wipe sampling in the occupational environment is a technique widely used by industrial hygienists. Although several organizations have promulgated standards for sampling lead and other metals, uncertainty still exists when trying to determine an appropriate wipe sampling strategy and how to interpret sampling results. Investigators from the National Institute for Occupational Safety and Health (NIOSH) Health Hazard Evaluation Program have used surface wipe sampling as part of their exposure assessment sampling strategies in a wide range of workplaces. This article discusses wipe sampling for measuring lead on surfaces in three facilities: (1) a battery recycling facility; (2) a firing range and gun store; and (3) an electronic scrap recycling facility. We summarize our findings from the facilities and what we learned by integrating wipe sampling into our sampling plan. Wiping sampling demonstrated lead in non-production surfaces in all three workplaces and that the potential that employees were taking lead home to their families existed. We also found that the presence of metals such as tin can interfere with the colorimetric results. We also discuss the advantages and disadvantages of colorimetric analysis of surface wipe samples and the challenges we faced when interpreting wipe sampling results.

The development and comparison of collection techniques for inorganic and organic gunshot residues.

The detection and interpretation of gunshot residues (GSR) plays an important role in the investigation of firearm-related events. Commonly, the analysis focuses on inorganic particles incorporating elements derived from the primer. However, recent changes in ammunition formulations and possibility that particles from non-firearm sources can be indistinguishable from certain primer particles challenge the standard operational protocol and call for adjustments, namely the combination of inorganic and organic GSR analysis. Two protocols for the combined collection and subsequent analysis of inorganic and organic GSR were developed and optimised for 15 compounds potentially present in organic GSR (OGSR). These protocols were conceptualised to enable OGSR analysis by ultrahigh-performance liquid chromatography (UHPLC) coupled with UV detection and triple quadrupole tandem mass spectrometry (confirmation) and IGSR analysis by scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDX). Using liquid extraction, the extraction recoveries from spiked swabs and stubs were ~80 % (50-98 % for swabs, 64-98 % for stubs). When the mixed OGSR standard was applied to the hands and recovered in the way that is usual for IGSR collection, GSR stubs performed significantly better than swabs (~30 %) for the collection of OGSR. The optimised protocols were tested and compared for combined OGSR and inorganic GSR analysis using samples taken at a shooting range. The most suitable protocol for combined collection and analysis of IGSR and OGSR involved collection using GSR stubs followed by SEM-EDX analysis and liquid extraction using acetone followed by analysis with UHPLC.

Probabilistic Monte Carlo estimation for quantitative exposure assessment of lotion transfer via baby wipes usage.

Unique aspects of childhood exposure to products need childs specific exposure data. This study developed a probabilistic exposure model for lotion transfer to diapered skin through normal use of baby wipes in children up to 48 months of age. Monte Carlo simulations used baby wipe diary data from the US, Germany and the UK, body weight data from the US, and lotion transfer data from single and multiple wipes adjusting for separate diaper changes. The models predicted a declining number of wipes used/day with a reduction in lotion transfer as age and body weight increased. Experimental testing on multiple sequential wipes used on an overlapping area showed a reduction in lotion deposition by 23.9% after the first wipe. Overall, the weighted population average over the approximate diapering period of 0-36 months across the three geographies at 50th, 90th, & 95th percentiles, were between 130, 230, 260 mg/kg/day, respectively, and 150, 270, 310 mg/kg/day depending on whether a reduction due to overlap is implemented. The statistical model represents an effective strategy to determine exposure to baby wipes lotion for exposure based risk assessment.

Recent knowledge: Concepts of dermal absorption in relation to skin decontamination.

Skin decontamination is an important step mitigating percutaneous absorption through the stratum corneum (SC), which is also a highly complex process. Thus, understanding diffusion mechanisms and measuring dermal absorption rates are critical to protect humans from toxic exposures. Here, highly varied literature is placed in a biological and clinical perspective in regards to decontamination. Literature from PubMed and Surge Laboratory library files were searched and reviewed for relevance. Recent data have shown multiple layers of SC structural heterogeneity, which results in unique substance partitioning characteristics across the membrane. As such, attempts to model and understand this behavior in alternative in vitro membranes prove difficult. More synthetic and natural membranes are being explored as models for in vivo behavior. In addition, commonly accepted decontamination methods are undergoing risk assessment. These recent and varied literature findings update available knowledge regarding skin decontamination and its challenges, with a focus on dermal absorption.