Occupational asthma due to low molecular weight agents

Studying full-shift inhalation exposures to volatile organic compounds (VOCs) among Latino workers in very small-sized beauty salons and auto repair shops

Background

One in every 200 US jobs is in a beauty salon or auto repair shop, where workers are regularly exposed to volatile organic compounds (VOCs) that may cause a range of short- and long-term health issues. In these shops, Latino workers are overrepresented and lack culturally and linguistically appropriate industrial hygiene resources. This leaves a gap in knowledge on inhalation exposures to VOCs in this hard-to-reach and ubiquitous worker population.

Objective

Our goal was to recruit hard-to-reach, predominantly Spanish-speaking workers in beauty salons and auto repair shops and monitor total VOC inhalation exposures for over entire work shifts, with minimal impact on workers, clients, and business.

Methods

We developed and refined measurement and exposure assessment methods for personal and area full-shift VOC inhalation exposures.

Results

With minimal participant loss, we measured over 500 h of real-time, personal VOC exposures and recorded activities and other exposure factors for 47 participants, while also documenting chemical inventories and quantifying indoor area concentrations of specific VOCs among 10 auto repair shops and 10 beauty salons.

Conclusion

Lessons learned from our study can assist future studies of inhalation exposures in other hard-to-reach occupational populations.

Respiratory toxicity of persulphate salts and their adverse effects on airways in hairdressers: a systematic review

Objective

To review the literature on respiratory effects of persulfate salts (PS) or hair bleaches in hairdressers and animal models exploring mechanisms behind PS-induced asthma.

Methods

A systematic review according to the PRISMA guidelines was performed. Studies published from 2000 to July 2021 that fulfilled predefined eligibility criteria were retrieved. Data were not quantitatively synthesized due to the heterogeneity of study designs, outcomes and methods.

Results

Forty-two articles were included. PS are indicated as the main cause of occupational rhinitis and asthma in hairdressers, and one of the leading causes of occupational asthma in some European countries. Bleaching products are indicated as the most important factor for development of respiratory symptoms, lung function decline, and leaving the hairdressing profession. Risk estimates from a good quality prospective study showed up to 3.9 times higher risk for wheezing and breathlessness in hairdressers aged ≥ 40 years than in matched controls, and 20 times higher risk in hairdressers to develop respiratory symptoms from exposure to bleaching powder than controls. Pathophysiological mechanisms of the respiratory response to PS are not yet fully elucidated, but may include non-specific and specific immune responses.

Conclusions

Hairdressing is associated with a wide spectrum of respiratory adverse effects, of which bleaching products were indicated as the most hazardous. Preventive measures for reducing inhalatory exposure to PS in hair salons should be re-evaluated, including adopting occupational exposure limits at EU level, and encouraging use of safer bleach formulations.

PROSPERO registration number

CRD42021238118.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00420-022-01852-w.

Assessment of the Cytotoxic and Immunomodulatory Effects of Substances in Human Precision-cut Lung Slices

Respiratory diseases in their broad diversity need appropriate model systems to understand the underlying mechanisms and enable development of new therapeutics. Additionally, registration of new substances requires appropriate risk assessment with adequate testing systems to avoid the risk of individuals being harmed, for example, in the working environment. Such risk assessments are usually conducted in animal studies. In view of the 3Rs principle and public skepticism against animal experiments, human alternative methods, such as precision-cut lung slices (PCLS), have been evolving. The present paper describes the ex vivo technique of human PCLS to study the immunomodulatory potential of low-molecular-weight substances, such as ammonium hexachloroplatinate (HClPt). Measured endpoints include viability and local respiratory inflammation, marked by altered secretion of cytokines and chemokines. Pro-inflammatory cytokines, tumor necrosis factor alpha (TNF-α), and interleukin 1 alpha (IL-1α) were significantly increased in human PCLS after exposure to a sub-toxic concentration of HClPt. Even though the technique of PCLS has been substantially optimized over the past decades, its applicability for the testing of immunomodulation is still in development. Therefore, the results presented here are preliminary, even though they show the potential of human PCLS as a valuable tool in respiratory research.

Occupational Rhinitis Revisited: Emphasis on the Risk Factors in Saudi Industry

The European Academy of Allergy and Clinical Immunology (EAACI) Task Force defines occupational rhinitis (OR) as "an inflammatory disease of the nose, which is characterized by intermittent or persistent symptoms (i.e., nasal congestion, sneezing, rhinorrea, itching), and/or variable nasal airflow limitation and/or hypersecretion arising out of causes and conditions attributable to a particular work environment and not to stimuli encountered outside the workplace." The objectives of this review are to highlight the causes of OR in industrial settings in Saudi Arabia in order to alert primary healthcare physicians and other healthcare providers of the importance of diagnosing and managing OR to prevent further complications and present to the General Organization for Social Insurance (GOSI) evidence of the existence of OR in Saudi industrial sector. The literature search yielded no publications from Saudi Arabia that have investigated the prevalence of OR, but it is expected to be high judging from the high prevalence of allergic rhinitis in the country. The occupational groups that are at risk of developing OR include workers in the petrochemical industry, healthcare personnel, livestock and bird breeders, bakers, farmers, housewives and other occupations all of which are present in Saudi Arabia. Clinic and industry based research within Saudi Arabia is recommended to determine the prevalence of OR and to alert healthcare providers to suspect OR in all symptomatic working adults, including housewives and domestic helpers. Use of EAACI algorithm for the diagnosis and management of this condition will help to manage the condition and prevent the deterioration and further complications. Furthermore, diagnosis using internationally recognized guidelines and the results of the suggested epidemiologic surveys may convince GOSI to recognize OR as an occupational disease.

Assessment of immunotoxicity induced by chemicals in human precision-cut lung slices (PCLS)

Occupational asthma can be induced by a number of chemicals at the workplace. Risk assessment of potential sensitizers is mostly performed in animal experiments. With increasing public demand for alternative methods, human precision-cut lung slices (PCLS) have been developed as an ex vivo model. Human PCLS were exposed to increasing concentrations of 20 industrial chemicals including 4 respiratory allergens, 11 contact allergens, and 5 non-sensitizing irritants. Local respiratory irritation was characterized and expressed as 75% (EC25) and 50% (EC50) cell viability with respect to controls. Dose-response curves of all chemicals except for phenol were generated. Local respiratory inflammation was quantified by measuring the production of cytokines and chemokines. TNF-α and IL-1α were increased significantly in human PCLS after exposure to the respiratory sensitizers trimellitic anhydride (TMA) and ammonium hexachloroplatinate (HClPt) at subtoxic concentrations, while contact sensitizers and non-sensitizing irritants failed to induce the release of these cytokines to the same extent. Interestingly, significant increases in T(H)1/T(H)2 cytokines could be detected only after exposure to HClPt at a subtoxic concentration. In conclusion, allergen-induced cytokines were observed but not considered as biomarkers for the differentiation between respiratory and contact sensitizers. Our preliminary results show an ex vivo model which might be used for prediction of chemical-induced toxicity, but is due to its complex three-dimensional structure not applicable for a simple screening of functional and behavior changes of certain cell populations such as dendritic cells and T-cells in response to allergens.