Long-term dermal exposure to diisononyl phthalate exacerbates atopic dermatitis through oxidative stress in an FITC-induced mouse model

Diisononyl phthalate （DINP）, considered to be an environmentally friendly plasticizer, is now widely used. However, the toxic effects of DINP need to be examined, particularly the effects of long-term dermal DINP exposure. Research into the mechanisms underlying these effects is urgently needed. In this study we examined the exacerbation effect of long-term dermal exposure to DINP in flnorescein isothiocyanate （FITC）-induced contact hypersensitivity （CHS） in mice, and sought the potential molecular mechanisms. Forty-nine male Balb/c mice were subjected to a 40-day dermal exposure to saline or one of three concentrations of DINP and then three rounds of sensitization with vehicle or 0.5% FITC. The results of a histopathological examination and measurement of ear swelling as well as immunological and inflammatory biomarkers （total-immunoglobulin （Ig）E and Th cytokines） supported the notion that high doses of DINP may aggravate atopic dermatitis. We also showed that melatonin, an antioxidant, could decrease the levels of oxidative stress and alleviate FITC-induced CHS suggesting that oxidative stress may be one of the molecular mechanisms to explain the exacerbation effect induced by DINP.

Evaluation of the Effectiveness of Hygenall^©Leadoff^TMFoaming Soap in Reducing Lead on Workers’ Hands and the Uptake of Lead on Bridge Painting Projects

Although considerable research has been conducted regarding airborne lead exposures during lead paint removal, little data has been collected measuring the lead concentration on workers’ hands in the construction industry. As a result, there are gaps in our understanding of the effectiveness of a standard work practice control (handwashing) in the prevention and control of elevated blood lead levels (BLLs) in the workplace. The primary objective of this study was to assess if a National Institute for Occupational Safety and Health (NIOSH) formulation intended to remove lead from skin (Hygenall© LeadoffTM Foaming Soap) is more effective than a commonly used soap in the industrial painting industry (Zep Cherry Bomb Soap) in reducing the concentration of lead on workers’ hands after exposure. A secondary aim was to assess if using LeadoffTM Foaming Soap during handwashing reduces worker uptake of lead on bridge painting projects. We evaluated hand wipe, air sample and blood lead level data collected by two industrial bridge painting contractors. Airborne exposures ranged from 350 μg/m3 to 19,700 μg/m3. The geometric mean lead concentration remaining on workers’ hands after using Zep Cherry Bomb Soap was 77 μg per hand wipe compared with 61 μg per hand wipe after use of LeadoffTM Foaming Soap for all work classifications. The geometric lead concentration on workers’ hands decreased by 16 μg/hand wipe for all work classifications combined after using LeadoffTM Foaming Soap—a decrease of 21%. The use of Hygenall LeadoffTM Foaming Soap reduced the maximum lead concentration on workers’ hands by 85%. The geometric mean BLL for all work classifications was 12.1 μg/dl before the use of LeadoffTM. After two months of airborne exposure and use of LeadoffTM Foaming Soap at breaks and at the end of the workday, the geometric mean BLL for all work classifications increased to 18.1 μg/dl. Worker BLLs increased despite the reduction in the concentration of lead measured on workers’ hands—most likely a result of ineffective inhalation exposure controls. We found that the LeadoffTM Foaming Soap was more effective in removing lead from workers’ hands than Zep Cherry Bomb.

Characteristics and health risks of population exposure to phthalates via the use of face towels

The production of face towels is growing at an annual rate of about 4%in China,reaching 1.13 million tons by 2021.Phthalates(PAEs)are widely used in textiles,and face towels,as an important household textile,may expose people to PAEs via the skin,further leading to health risks.We collected new face towels and analyzed the distribution characterization of PAEs in them.The changes of PAEs were explored in a face towel use experiment and a simulated laundry experiment.Based on the use of face towels by 24 volunteers,we calculated the estimated daily intake(EDI)and comprehensively assessed the hazard quotient(HQ),hazard index(HI),and dermal cancer risk(DCR)of PAEs exposure in the population.PAEs were present in new face towels at total concentrations of<MDL–2388 ng/g,with a median of 173.2 ng/g,which was a lower contamination level compared with other textiles.PAE contents in used face towels were significantly higher than in new face towels.The concentrations of PAEs in coral velvet were significantly higher than those in cotton.Water washing removed some PAEs,while detergent washing increased the PAE content on face towels.Gender,weight,use time,and material were the main factors affecting EDI.The HQ and HIwere less than 1,which proved PAEs had no significant non-carcinogenic health risks.Among the five target PAEs studied,DEHPwas the only carcinogenic PAE andmay cause potential health risks after long-term exposure.Therefore,we should pay more attention to DEHP.

Assessment of potential dermal and inhalation exposure of workers to the insecticide imidacloprid using whole-body dosimetry in China

In China, although improvements to the pesticide registration process have been made in la thirty years, no occupational exposure data are required to obtain a commercial license for pesticide product. Consequently, notably little research has been conducted to establish a exposure assessment procedure in China. The present study monitored the potential derm operator exposure from knapsack electric sprayer wheat field application of imidacloprid Liaocheng City, Shandong Province and in Xinxiang City, Henan Province, China, usin whole-body dosimetry. The potential inhalation exposure was determined using a person air pump and XAD-2 sample tubes. The analytical method was developed and validate including such performance parameters as limits of detection and quantification, linear rang recovery and precision. The total potential dermal and inhalation exposures were 14.20, 16.815.39 and 20.78 mL/hr, respectively, for the four operators in Liaocheng and Xinxian corresponding to 0.02% to 0.03% of the applied volume of spray solution. In all trials, the low part（thigh, lower leg） of the body was the most contaminated, accounting for approximate76% to 88% of the total exposure. The inhalation exposure was less than 1% of the tot exposure. Such factors as the application pattern, crop type, spray equipment, operat experience and climatic conditions have been used to explain the exposure distribution ov the different parts of the body. As indicated by the calculated Margin of Exposure, the typic wheat treatment scenarios when a backpack sprayer was used are considered to be safe terms of imidacloprid exposure.