Cypermethrin, a member of the synthetic pyrethroids group, is a popular insecticide used to elimi... more Cypermethrin, a member of the synthetic pyrethroids group, is a popular insecticide used to eliminate a broad range of common bugs in agricultural lands and households. However, studies of farmers’ exposure to this insecticide are limited. The present study aimed to measure the respiratory exposure to cypermethrin among farmers and farm workers of Shiraz, as one of the biggest cities in Fars province, Iran. Totally, nine target regions were selected, where 42 individual samples were taken using XAD-2 sorbents and were analyzed by gas chromatography-electron capture detector (GC-ECD). This is the first study on farmers’ exposure to insecticides during spraying in Iran. The average concentration of cypermethrin vapor in farmers’ respiratory area during spraying was 0.982 ± 0.421 mg/m3, which was lower than the permitted threshold value for cypermethrin recommended by the Occupational Safety and Health Administration (OSHA). The mean time-weighted average (TWA) was also evaluated in two distinct occupational groups (tree operators and field operators). The exposure was significantly higher in tree operators than in field operators. A direct correlation was also found between the height of the workers and the amount of cypermethrin (Spearman’s r = 0.555). Findings support that farm workers’ respiratory exposure to cypermethrin was within the permissible range, but this situation cannot guarantee workers’ safety. Total respiratory exposure and skin exposure studies are recommended in future research.
Gold nano particles (GNP) were deposited on Na-Y and H-Y zeolite substrates using chloroauric aci... more Gold nano particles (GNP) were deposited on Na-Y and H-Y zeolite substrates using chloroauric acid (HAuCl4) solution. The synthesized catalysts were then characterized and the catalytic activity toward CO oxidation reaction was investigated using a tubular fix bed micro reactor under atmospheric pressure. It was found that CO conversion of 100% and 5% can be achieved at 20 °C on Au/Na-Y and Au/H-Y fresh catalysts, respectively. Thermal stability of catalysts was also investigated by treating the catalysts at 400 °C for 4 h. After thermal stability test, activity tests of the catalysts at 20 °C were shown that CO conversion of Au/Na-Y catalyst was decreased to 65% whereas the activity of the Au/H-Y at 20 °C was increased up to 15%. Characterization tests were revealed that the structures of the zeolitic supports were remained unchanged after thermal pretreatment.
Cypermethrin, a member of the synthetic pyrethroids group, is a popular insecticide used to elimi... more Cypermethrin, a member of the synthetic pyrethroids group, is a popular insecticide used to eliminate a broad range of common bugs in agricultural lands and households. However, studies of farmers’ exposure to this insecticide are limited. The present study aimed to measure the respiratory exposure to cypermethrin among farmers and farm workers of Shiraz, as one of the biggest cities in Fars province, Iran. Totally, nine target regions were selected, where 42 individual samples were taken using XAD-2 sorbents and were analyzed by gas chromatography-electron capture detector (GC-ECD). This is the first study on farmers’ exposure to insecticides during spraying in Iran. The average concentration of cypermethrin vapor in farmers’ respiratory area during spraying was 0.982 ± 0.421 mg/m3, which was lower than the permitted threshold value for cypermethrin recommended by the Occupational Safety and Health Administration (OSHA). The mean time-weighted average (TWA) was also evaluated in two distinct occupational groups (tree operators and field operators). The exposure was significantly higher in tree operators than in field operators. A direct correlation was also found between the height of the workers and the amount of cypermethrin (Spearman’s r = 0.555). Findings support that farm workers’ respiratory exposure to cypermethrin was within the permissible range, but this situation cannot guarantee workers’ safety. Total respiratory exposure and skin exposure studies are recommended in future research.
Gold nano particles (GNP) were deposited on Na-Y and H-Y zeolite substrates using chloroauric aci... more Gold nano particles (GNP) were deposited on Na-Y and H-Y zeolite substrates using chloroauric acid (HAuCl4) solution. The synthesized catalysts were then characterized and the catalytic activity toward CO oxidation reaction was investigated using a tubular fix bed micro reactor under atmospheric pressure. It was found that CO conversion of 100% and 5% can be achieved at 20 °C on Au/Na-Y and Au/H-Y fresh catalysts, respectively. Thermal stability of catalysts was also investigated by treating the catalysts at 400 °C for 4 h. After thermal stability test, activity tests of the catalysts at 20 °C were shown that CO conversion of Au/Na-Y catalyst was decreased to 65% whereas the activity of the Au/H-Y at 20 °C was increased up to 15%. Characterization tests were revealed that the structures of the zeolitic supports were remained unchanged after thermal pretreatment.
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