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Introduction: Magnetite as iron oxide is widely used in various industries, in the pharmaceutical industry in particular where it is used for its magnetic properties. The environmental and occupational exposure to airborne nanoparticles and microparticles of iron oxide compounds have been reported. Since authors have reported contradictory results, the objective of this study was to investigate the effect of particles’ size in their toxicities. Methods: The human cell line A549 was exposed with magnetite iron oxide in two size categories of micro (≥5 µm) and nano (<100 nm), with four concentrations of 10, 50, 100, and 250 µg/ml at two time periods of 24 and 72 h. The cell viability, reactive oxygen species (ROS), changes in mitochondrial membrane potential, and incidence of apoptosis were studied. Results: Nano and micro magnetite particles demonstrated diverse toxicity effects on the A549 cell line at the 24- and 72-h exposure periods; however, the effects produced were time- and concentration-dependent. Nano magnetite particles produced greater cellular toxicities in forms of decreased viabilities at concentration exposures greater than 50 µg/ml ( p < 0.05), along with increased ROS ( p < 0.05), decreased cellular membrane potential ( p < 0.05), and reduced rate of apoptosis ( p < 0.05). Discussion: The results of this study demonstrated that magnetite iron in nano-range sizes had a greater absorbability for the A549 cell line compared to micro sizes, and at the same time, nanoparticles were more toxic than microparticles, demonstrating higher production of ROS and decreased viabilities. Considering the greater toxicity of nanoparticles of magnetite iron in this study, thorough precautionary control measures must be taken before they can be used in various industries.

The toxicity of carbon nanotubes (CNTs) toward the mitochondria of the kidney is not fully recognized and still needs further research. Apigenin (APG) is known as a flavonoid compound and natural antioxidant. The purpose of this study was to assess the ameliorative role of APG against multiwall CNT (MWCNT)-induced kidney toxicity in rats. The animals were administrated with APG (10 mg/kg) for 2 weeks and then were exposed to MWCNTs (5 mg/m 3 ) in pure and impure forms (10 and 100 nm) for 5 h/day and 5 days/week. Then, mitochondria were isolated from the kidney tissue and mitochondrial toxicity parameters were measured. Decreases in succinate dehydrogenase activity have been reported in all groups exposed to MWCNTs. Results indicated that MWCNTs in both forms and sizes were able to increase the generation of reactive oxygen species, decline mitochondrial membrane potential, induce mitochondrial swelling, and release cytochrome c in isolated kidney mitochondria. The pretreatment of APG decreased all the abovementioned mitochondrial damage and oxidative stress parameters induced by both pure and impure MWCNTs. Our results showed that MWCNTs have the ability to enter the body, subsequently, cross cellular barriers, and reach the kidney as a sensitive organ, which can result in mitochondrial damage in kidney cells including renal tubular cells. In addition, APG can be an effective nutritional antioxidant regimen against MWCNT-induced kidney damage.

Treatment using cytotoxic drugs is considered to be the most common treatment for cancers. However, the widespread use of these drugs on the health status of the staff at the oncology department has become a great concern. Due to challenges of sampling and analysis of cytotoxic drugs, the aim of this study was to development a novel practical method called Needle trap devices (NTD) for sampling and analysis of personal exposure to cyclophosphamide drug. The sampler consisted of a stainless steel hyper needle gauge 21 of length 9 cm packed with Carboxen 1000 for adsorbing cyclophosphamide. A total of 41 samples of staff's air breathing zone in different wards of the oncology department were taken with the sampler. Samples were analyzed by gas chromatography coupled with electron capture detector (ECD). Linear range concentration was 212-1062 μg/m(3), and LOD and LOQ were 100 and 191 μg/m(3), respectively. The mean inter-day and intra-day coefficient variations for standards within linear range concentration were 8.9 and 4.8 %, respectively. Detectable levels of cyclophosphamide were measured in 31.7 % of air samples. The developed method is user-friendly, quick, and precise for sampling of airborne cyclophosphamide. The results showed that some staff of the oncology department were exposed to the carcinogenic drug and their health were at risk. Since carcinogens do not have a threshold and oncology staffs with their continuous exposure might be at risk, therefore, proper work practice and adequate control measures are essential to ensure their wellbeing.

Our analysis shows diversity and ambiguity in the workplace health literature regarding domains and characteristics of a healthy/health promoting workplace. This may have roots in lack of a common understanding of the concepts or different social and work environment context. Development of global or national health promoting workplace standards in a participatory process might be considered as a potential solution.