Cancer risk assessment in welder's under different exposure scenarios

Welders exposure to nickel and hexavalent chromium in welding fumes is associated with increase of cancer risk in welders. In this study we calculated cancer risk due to exposure to these compounds in welders. The role of exposure parameters in welders on derived incremental lifetime cancer risk were determined by stochastic modeling of cancer risk. Input parameters were determined by field investigation in Iranian welders in 2013 and literature review. The 90% upper band cancer risk due to hexavalent chromium and nickel exposure was in the range of 6.03E-03 to 2.12E-02 and 7.18E-03 to 2.61E-02 respectively. Scenario analysis showed that asthmatic and project welders are significantly at higher cancer risk in comparison with other welders [P<0.05]. Shift duration was responsible for 37% and 33% of variances for hexavalent chromium and nickel respectively. Welders are at high and unacceptable risk of cancer. Control measures according to scenario analysis findings are advisable

Evaluation of occupational exposure of glazers of a ceramic industry to cobalt blue dye

Cobalt is one of the most important constituent present in ceramic industries. Glazers are the relevant workers when they are producing blue colored ceramic, causing occupational exposure to such metal. Through this study, urinary cobalt was determined in glazers in a ceramic industry when they were producing blue-colored ceramic glazes. In this case-control study, spot urine samples were collected from 49 glazers at the start and end of work shifts [totally 98 samples] in 2011. Control group were well matched for age, height, and weight. A solid phase extraction system was used for separation and preconcentration of samples followed by analysis by inductively coupled plasma-atomic emission spectroscopy [ICP-AES]. All participants filled out a self administered questionnaire comprises questions about duration of exposure, work shift, use of mask, skin dermatitis, kind of job, ventilation system, overtime work, age, weight, and height. The lung function tests were performed on each control and cobalt exposed subjects. Analysis of covariance [ANCOVA] was used to evaluate the obtained results. Urinary levels of cobalt were significantly higher in the glazers compared to the control group. There were significant differences at urinary concentration of cobalt at the start and end of the work shift in glazers. Spirometric parameters were significantly lower in the glazers compared to the control group. Among the variables used in questionnaire the significant variables were dermatitis skin, mask, ventilation, and overtime work. This study verified existence of cobalt in the urine glazers showing lower amount than the ACGIH standard

Effect of zinc oxide nanoparticles on viability of human spermatozoa

The extensive use of different nanoparticles has raised great concerns about their occupational and biological safety. The aim of this study was to evaluate the cytotoxic effect of zinc oxide nanoparticles [ZnO NPs] on viability of spermatozoa. Semen samples were obtained from 15 healthy persons, and were analyzed using WHO guidelines. Each semen sample was separately incubated with different concentrations of ZnO NPs [10, 100, 500, and 1000 micro g/mL] at 37°C for 45, 90, and 180 minutes. Then, the cell death percentage of spermatozoa was measured by MTT assay. Mann-Whitney test was used for comparison of different times and concentrations. The maximum cell death percentage was 20.8%, 21.2%, and 33.2% after 45, 90, and 180 minutes, respectively. In case of concentration, the highest concentration [1000 micro g/mL] of ZnO NPs led to the highest toxicity for all incubation times. Statistically, there were significant differences in cell viability after 180 minutes vs.45 and 90 minutes. This study indicated that cytotoxicity of ZnO NPs is dose and time dependent

Lectin histochemistry of cholesterol cleft granulomas in non-specific interstitial pneumonia [NSIP]

Cholesterol cleft granulomas with clusters of giant cells were noted to be a common feature of non-specific interstitial pneumonia [NSIP].This study aimed to define the cell populations involved in the granulomas.The granulomas of 16 patients with cryptogenic fibrosing alveolitis [five cases with the histological features of NSIP, five with those of UIP and six cases of respiratory bronchiolitis] were examined histologically and by the use of immuno- and lectin histochemical markers.Granulomas were discrete, compact and present only in alveolar spaces. The adjacent interstitium usually showed fibrous thickening although granulomas were absent. The granulomas contained central clefts surrounded by mononuclear and multi-nucleated giant cells, both of which were CD68 positive. The cells outside the granulomas and those lining the adjacent alveolar walls were AE1/AE3 and CAM5.2 positive and CD68 negative. The application of an extended lectin panel demonstrated restricted glycoprofiles for multinucleated cells, alveolar macrophages and alveolar lining cells. The glycoprofiles of the first two were similar to each other, but were different from the third. The mononuclear and multinucleated cells of cholesterol cleft granulomas are derived from the macrophage-mononuclear cell lineage and express glyco-proteins with a high mannose content. The alveolar lining cells are type n pneumocytes which do not contribute to the granuloma cell population