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Exposure to chemical and physical factors occur in many occupations. Exposure to ambient pollutants such as noise, heavy metals, drugs enhance free radicals and can cause oxidative stress. The aim of the present project was to investigate noise and lead as two workplace stressors in rats. 20 male rats were assigned into 4 groups randomly. Rats in control group was not exposed to any stressor agent, while the first group was exposed to noise (105 dB, 4 kHz), the second group was exposed to lead acetate (gavage,4 mg/kg), and the last group was exposed to both lead and noise. In order to assess oxidative stress, the serum levels of malondialdehyde (MDA), as a product of lipid peroxidation was measured by thiobarbituric acid and also total antioxidant capacity (TAC) were measured by using ELISA kits. Our research showed significant enhancement in levels of malondialdehyde in exposed groups compare to control group. Also our results showed considerable decrease in levels of TAC in exposed groups compared to control group. Lead and noise exposure for 30 days caused a statistically significant enhancement in MDA level and significant decrease in the serum TAC level. On the other hand, statistically no significant difference was observed between the MDA and TAC levels between exposed groups. Moreover, body weight between exposed groups have decreased compared to control group. The outcomes of this study confirms the effect of noise and lead on lipid peroxidation. However, further studies are needed to clarify the mechanisms of oxidative stress through lead and noise exposure.

The public concern of harmful effects of radiofrequency radiation exposure, especially with rapid increase in the use of wireless and telecommunication devices, is increasing. Some studies show fetal and developmental abnormalities as the result of radiofrequency radiation exposure. We aimed to investigate possible teratogenic effects of radiofrequency in 915 MHz on mice fetus and protective role of vitamin C. 21 pregnant mice were divided into 3 groups. Control group was in normal condition without any stressor agent. Exposure group was exposed to 915 MHz RFR (8 h/day for 10 days) and 0.045 µw/cm2 power density. The exposure plus vitamin C group received 200 mg/kg vitamin C by gavage and was exposed to 915 MHz RFR (8 h/day for 10 days) and 0.045 µw/cm2 power density. The fetus weight, C-R length were measured by digital balance and caliper. Tissues were assessed after staining with H & E. Our results showed significant increase in fetus weight and C-R length and also enlarged liver, tail deformation in mice fetus in exposure group. Although usage of vitamin C caused significant decrease in mentioned parameters. The outcome of this study confirms the effects of radiofrequency radiation on growth parameters such as body weight, length and some tissues in mice fetuses and protective effect of vitamin C. However more studies on non-ionization radiation in different frequencies and severity, during pregnancy are needed to clarify the exact mechanisms of these changes and better protection.

Background: Lead is a major environmental pollutant and can adversely affect humans and animals. There are conflicting data about the ototoxic effect of lead. This study experimentally examined the association between blood lead levels (BLL) and the subsequent hearing impairment in male rats. Methods: Twenty-two male rats were randomly categorized into experimental (exposed to lead acetate, 4 mg/kg by gavage) and control groups. We evaluated the groups by click and tone audiometric burst tests, comparing the data before and 30 days after exposure to lead acetate (4mg/kg). Also, blood samples were collected from the rats and analyzed for lead levels by graphite furnace atomic absorption spectrometry. Results: The study findings demonstrated remarkable increase in hearing threshold in the lead-exposed group, compared to the controls (p<0.0001). Also, the blood lead levels revealed a significant association of lead acetate with the hearing loss in rats. Conclusion: This study revealed that exposure to lead acetate can be damaging to hearing. However, future research is recommended to clarify the mechanism of action of lead toxicity on the auditory function at varying blood lead concentrations.

Background and Objective: Given the necessity of assessing knowledge and practice of individuals to prevent the Aflatoxin contamination in pistachio in order to develop appropriate educational interventions, design and validating a standard tool is essential. Therefore, the purpose of this study was to develop and validate an instrument to determine the knowledge and performance of pistachio farmer in terms of Aflatoxin contamination and the methods to prevent its production in pistachio product. Materials and Methods:In this research, initial items of instrument were designed based on literature review and interview with experts and farmers. The face validity, Content Validity Ratio (CVR) and Content validity Index (CVI) of instrument were determined by interview with farmers and through opinions of experts' panel respectively. Test-retest analysis was conducted to test the stability of the instrument. Also, according to the data of 380 farmers, exploratory factor analysis (EFA) was performed. Results: The results showed that CVI and CVR of items of instrument were ≤0.79 and ≤0.62 respectively. Confirmatory factor analysis indicated a good fit for the data. EFA Analysis showed that KMO is suitable for 3 groups of Knowledge and also for practice. Bartlett's test was significant and zero hypothesis of data was rejected. According to factor load higher than 0.3 for every question, neither of them was removed. Finally, questionnaire of Knowledge was confirmed with 18 and Practice questionnaire was confirmed with 10 questions. Conclusion: The developed instrument can be used to measure the knowledge and practice of pistachio farmers about Aflatoxin contamination, as a research tool, to be used to develop appropriate educational interventions.