Inhalation of tungsten metal particulates alters the lung and bone microenvironments following acute exposure

Inhalation of tungsten particulates is a relevant route of exposure in occupational and military settings. Exposure to tungsten alloys is associated with increased incidence of lung pathologies, including interstitial lung disease and cancer. We have demonstrated, oral exposure to soluble tungsten enhances breast cancer metastasis to the lungs through changes in the surrounding microenvironment. However, more research is required to investigate if changes in the lung microenvironment, following tungsten particulate exposure, can drive tumorigenesis or metastasis to the lung niche. This study examined if inhalation to environmentally relevant concentrations of tungsten particulates caused acute damage to the microenvironment in the lungs and/or systemically using a whole-body inhalation system. Twenty-four female BALB/c mice were exposed to Filtered Air, 0.60 mg/m3, or 1.7 mg/m3 tungsten particulates (< 1 µm) for 4 h. Tissue samples were collected at day 1 and 7 post-exposure. Tungsten accumulation in the lungs persisted up to 7 days post-exposure and produced acute changes to the lung microenvironment including increased macrophage and neutrophil infiltration, increased levels of pro-inflammatory cytokines IL-1β and CXCL1, and an increased percentage of activated fibroblasts (α-SMA+). Exposure to tungsten also resulted in systemic effects on the bone, including tungsten deposition and transient increases in gene expression of pro-inflammatory cytokines. Taken together, acute whole-body inhalation of tungsten particulates, at levels commonly observed in occupational and military settings, resulted in changes to the lung and bone microenvironments that may promote tumorigenesis or metastasis and be important molecular drivers of other tungsten-associated lung pathologies such as interstitial lung disease.

Infertility: A product of smoke emanating from Transfluthrin coated insecticide paper (TCIP)

Transfluthrin is a fast-acting insecticide used in household and hygiene products, mainly against flying insects, such as mosquito and flies, and in agriculture material pests. Its uses in these areas have not been without health risk to humans and the ecosystem. Therefore, the current study was designed to investigate the effect of smoke emanating from Transfluthrin Coated Insecticide Paper (TCIP) on adult Wistar rats’ testicular functions. The rats were grouped into three. Group A was exposed to normal environmental air. Group B and C rats were exposed via whole-body inhalation to smoke emanating from 6 g and 12 g of TCIP every day for 8 weeks. The entire groups contained eight rats each. At the end of the exposure, body and organs weight, semen analysis, biochemical assay and histological examination were evaluated and determined. The results show that the exposure significantly altered the testicular cytoarchitecture, sperm quality, hormonal profile and oxidative parameters with an increase in exposure to TCIP. This study revealed that exposure to transfluthrin is detrimental to the reproductive functions of male rats.

Comparative Analysis of the Exploratory Activity of Rats Following the Administration of Liquid Aerosol Using “Nose Only” and “Whole Body” Inhalation Chambers

The use of various models of inhalational drug administration in pre-clinical studies is strongly limited due to the influence of liquid aerosol on the exploratory behaviour of small laboratory rodents. There are two approaches to modelling inhalational administration, which involve two types of chambers: “whole-body” and “nose-only”. In this work, we compared a change in the parameters of exploratory behaviour depending on the type of chambers used.