Field protection effectiveness of chemical protective suits and gloves evaluated by biomonitoring

Oxime-functionalized anti-insecticide fabric reduces insecticide exposure through dermal and nasal routes, and prevents insecticide-induced neuromuscular-dysfunction and mortality

Farmers from South Asian countries spray insecticides without protective gear, which leads to insecticide exposure through dermal and nasal routes. Acetylcholinesterase plays a crucial role in controlling neuromuscular function. Organophosphate and carbamate insecticides inhibit acetylcholinesterase, which leads to severe neuronal/cognitive dysfunction, breathing disorders, loss of endurance, and death. To address this issue, an Oxime-fabric is developed by covalently attaching silyl-pralidoxime to the cellulose of the fabric. The Oxime-fabric, when stitched as a bodysuit and facemask, efficiently deactivates insecticides (organophosphates and carbamates) upon contact, preventing exposure. The Oxime-fabric prevents insecticide-induced neuronal damage, neuro-muscular dysfunction, and loss of endurance. Furthermore, we observe a 100% survival rate in rats when repeatedly exposed to organophosphate-insecticide through the Oxime-fabric, while no survival is seen when organophosphate-insecticide applied directly or through normal fabric. The Oxime-fabric is washable and reusable for at least 50 cycles, providing an affordable solution to prevent insecticide-induced toxicity and lethality among farmers.

Prevention of pesticide-induced neuronal dysfunction and mortality with nucleophilic poly-Oxime topical gel

Organophosphate-based pesticides inhibit acetylcholinesterase (AChE), which plays a pivotal role in neuromuscular function. While spraying in the field, farmworkers get exposed to pesticides through the dermal route. Internalized pesticide inhibits AChE, which leads to neurotoxicity, cardiotoxicity, cognitive dysfunction, loss of endurance, and death in severe cases. Here, we present a nucleophilic pyridine-2-aldoxime-functionalized chitosan-based topical gel (poly-Oxime gel) that rapidly deactivates organophosphates, methyl parathion (MPT), on the skin of rats, which leads to reduced AChE inhibition in the blood and tissues. Testing the robustness of poly-Oxime gel, we report reduction in AChE inhibition following repeated dermal administration of MPT in the presence of poly-Oxime gel. Furthermore, poly-Oxime gel prevented MPT-induced neuromuscular dysfunction, loss of endurance, and locomotor coordination. We observe a 100% survival in rats following topical MPT administration in the presence of poly-Oxime gel. This prophylactic gel may therefore help farmworkers by limiting pesticide-induced toxicity and mortality.

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.

Barrier cream based on CeO2 nanoparticles grafted polymer as an active compound against the penetration of organophosphates

Due to their small size, nanoparticles possess unique properties. Cerium oxide nanoparticles have been already studied for their capacity to adsorb and neutralize toxic compounds including organophosphates. By covalently grafting these nanoparticles to a thickening polymer, their potential aggregation resulting in a loss of surface area and their potential toxicity are avoided. Indeed, copolymers easily form gels in water at neutral pH thanks to low interactions occurring between polymeric chains; thus, gels can be spread on membrane supports to afford protective barriers. However, as we demonstrated previously, a formulation step of these hydride nanoparticle-polymeric compounds is necessary to overcome the cracking of the coating during drying. This work reports the impact of many factors on the efficiency of a new active Topical Skin Protectant (aTSP) including: (1) the presence of CeO₂ nanoparticles in the protective coating and their amount, (2) their grafting to a perfluorocarbon thickening polymer and (3) the formulation of the CeO₂ nanoparticle-grafted polymer. The combination of all the benefit parameters led to a very effective new aTSP against paraoxon penetration. The major in vitro diffusion studies were performed in Franz-type diffusion cells on two artificial membranes (silicone and Strat-M) and final validation on ex vivo human skin. The comparison of 24 h-exposure between membrane results indicated a difference in the behavior between the two artificial supports and the biological model; Strat-M membranes seeming closer to human skin results. Therefore, positive results regarding occlusive conditions should be confirmed with human skin.

New CeO2 nanoparticles-based topical formulations for the skin protection against organophosphates

To reinforce skin protection against organophosphates (OPs), the development of new topical skin protectants (TSP) has received a great interest. Nanoparticles like cerium dioxide (CeO₂) known to adsorb and neutralize OPs are interesting candidates for TSP. However, NPs are difficult to disperse into formulations and they are suspected of toxicological issues. Thus, we want to study: (1) the effect of the addition of CeO₂ NPs in formulations for the skin protection (2) the impact of the doping of CeO₂ NPs by calcium; (3) the effect of two methods of dispersion of CeO₂ NPs: an O/W emulsion or a suspension of a fluorinated thickening polymer (HASE-F) grafted with these NPs. As a screening approach we used silicone membranes as a skin equivalent and Franz diffusion cells for permeation tests. The addition of pure CeO₂ NPs in both formulations permits the penetration to decrease by a 3–4-fold factor. The O/W emulsion allows is the best approach to obtain a film-forming coating with a good reproducibility of the penetration results; whereas the grafting of NPs to a thickener is the best way to obtain an efficient homogenous suspension of CeO₂ NPs with a decreased of toxicological impact but the coating is less film-forming which slightly impacts the reproducibility of the penetration results.

An experimental study on the ergonomics indices of partial pressure suits

Partial pressure suits (PPSs) are used under high altitude, low-pressure conditions to protect the pilots. However, the suit often limits pilot's mobility and work efficiency. The lack of ergonomic data on the effects of PPSs on mobility and performance creates difficulties for human factor engineers and cockpit layout specialists. This study investigated the effects of PPSs on different ergonomic mobility and performance indices in order to evaluate the suit's impact on pilot's body mobility and work efficiency. Three types of ergonomics indices were studied: the manipulative mission, operational reach and operational strength. Research results indicated that a PPS significantly affects the mobility and operational performance of the wearers. The results may provide mission planners and human factors engineers with better insight into the understanding of pilots' operational function, mobility and strength capabilities when wearing PPS.

Genotoxic damage in auto body shop workers

Some studies have shown increased DNA damage among car painters, but other professionals working in auto body and paint shops have not been extensively assessed. The aim of this study was to assess DNA damage in different types of auto body shop workers by measuring micronucleus (MN) levels in exfoliated buccal cells. The mean number of cells with MN per 2000 exfoliated buccal cells was analyzed in three groups of male workers: auto body repair technicians, painters, and office workers (control group). All participants answered a questionnaire inquiring about age, smoking habits, alcohol consumption, work practices, occupational exposure time, job activities, and use of protective equipment. The mean number of cells with MN was 3.50 ± 1.50 in auto body painters, 3.91 ± 2.10 in auto body repair technicians, and 0.80 ± 0.78 in office workers, with a significant difference between the control group and the two other groups (p = 0.0001). Age, occupational exposure time, use of protective masks, alcohol consumption, and smoking habit did not affect MN results. The findings indicate that technicians and painters working in auto body shops are at risk for genotoxic damage, while office workers seem to be protected.

Farmer exposure to organic solvents during the maintenance and repair of farm machinery: a pilot study

BACKGROUND

The maintenance/repair of farm machinery is a common farming activity. Dermal exposure to organic solvents has not been well documented. A pilot study was conducted to characterize exposure to organic solvents.

METHODS

A survey questionnaire was administered to 31 Kentucky farmers in 2008. Dermal exposure assessment was conducted in 10 farmers while farmers performed farm machinery maintenance/repair tasks using a solvent sampling patch. Benzene, toluene, xylene, and n-hexane were analyzed.

RESULTS

All four organic solvents were identified from the samples with toluene (<0.5-36,000 microg/patch) and xylene (15-5,700 microg/patch) at significantly higher levels. Twenty-six farmers reported the use of personal protective equipment <50% of their time repairing/maintaining farm machinery on the questionnaire; only two farmers wore gloves during the exposure assessment.

CONCLUSIONS

Farmers routinely use solvent products for farm machinery maintenance/repair. Dermal exposure to organic solvents is a potential hazard. Further studies to characterize and evaluate exposure in larger samples of farmers are needed.