Journal of School of Public Health and

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Myiasis is always resulted by depositionof egg or young larvae of cyclorrhapha flies’ in live tissus of human or animals,which follows by their Development. Although the survival of mentioned larves is depended on existance of livestock and wild animals, the flies can be seen in parks, dairy farms and certain plants and also solid wasts waiting for proper hosts. The frequent study was carried out in Tehran and suburb and adalt flies were netted in different areas, indoors and outdoors and taken to the laboratory for identification. Twenty-two species of flies were identified. Thirteen species were medically important and four species consisting: Calliphora vomitoria, Lucilia richardsi, sarcophaga fertoni, Sarcophaga peregrina were identified and reported for the first time in Iran.

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Background and aim: The chromium mist generator is an essential tool for research and for making evidence-based recommendations in evaluating air pollution and its control systems. The purpose of this study was to design and construct a homogeneous chromium mist generator and to look at the effects of factors such as sampling height and distance between samplers in side-by-side sampling on the chromium mist sampling method.
Material and Methods: First we developed a mist generator, using a chromium electroplating bath in pilot scale. Concentrations of CrO3 and sulfuric acid in plating solution were 125 g L-1 and 1.25 g L-1, respectively. To set up permanent air sampling locations, a Plexiglas cylindrical chamber (75 cm height, 55 cm i.d) was installed as the bath overhead. Sixty holes were made on the chamber in 3 rows (20 in each row). The distance between rows and holes was 15 and 7.5 cm, respectively. Homogeneity and the related factors were studied using a side-by-side air sampling method. Forty-eight clusters of samples were collected on polyvinyl chloride (PVC) filters contained in sampling closed-face cassettes. Cassettes were located 35, 50, and 65 cm above the solution surface with < 7.5 and/or 7.5-15 cm distance between heads. All samples were analyzed by the NIOSH method 7600.
Results: ANOVA tests showed no significant differences between locations in side-by-side sampling (P=0.82) or between different sampling heights or sampler distances (P=0.86 and 0.86, respectively). However, there were notable differences between means of coefficients of variation (CV) in various heights and distances.
Conclusion: We conclude that the most chromium mist homogeneity could be obtained at a height of 50 cm from the bath solution surface and with a distance of < 7.5 cm between samplers.

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Background and Aim: Hexavalent chromium (Cr⁶⁺) is a known occupational carcinogen. Over the recent years, the increasing number of exposed workers and the emergence of serious health effects have led to considerable lowering of permissible exposure levels for Cr⁶⁺. Moreover, a number of methods have been developed for rapid and precise measurement of Cr⁶⁺concentrations. Given the importance of accurate measurements, this study was carried out to compare the performance of different samplers in relation to factors such as sampling height, sampling duration, and electroplating solution concentration.

Material and Methods: We used a hexavalent chromium generator fitted with a special sampling chamber and with proven ability to produce homogenous atmospheric concentrations. The performances of 4 samplers including IOM and CIS (as inhalable particle samplers) and Open and Closed-face cassettes (as total particle samplers) were examined through a simultaneous sampling technique. Sampling was done using the NIOSH 7600 method (samples were collected on PVC membrane filters with a pore size of 5.0 µm, at an air flow rate of 2.0 ± 0.1 l/min). Variables investigated with regard to their effects on sampler performance were sampling height (heights from bath solution: 35 and 50 cm), duration (30 and 180 min) and solution concentration (125 and 250 g/l).

Results: The measured concentrations ranged from 2 to 2725 µg.m^-3. Analysis of the results in a completely randomized block design showed significant differences in performance between different samplers (P< 0.001). There were also differences between samplers at different heights and electroplating concentrations (P=0.0007). Multiple comparisons by Scheffe's method showed that the difference detected was due to the superior precision of the IOM (P<0.05).

Conclusion: Overally, there were statistically significant differences between the performances of the studied samplers Cr⁶⁺ concentrations at the studied heights (4.09, 8.68 µg.m^-3), sampling duration (5.90, 6.88 µg.m^-3), and bath concentration (2.73, 11.88 µg.m^-3) had no significant effects on sampler performance. The CIS sampler underwent corrosion during acidic mist collection and thus can not be recommended for Cr⁶⁺ mist collection.

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Background and Aim: Exposure to hexavalent chromium in plating operations is associated with skin ulceration, contact dermatitis, respiratory tract irritation, cancer, and kidney damage. We investigated the possibility of using biological monitoring to assess exposure to hexavalent chromium in chrome-plating workers. We compared mean Cr6 concentrations in the breathing zone plus urine chromium, β2 microglobulin (B2M), and N-acetyl-B-D- glucosaminidase (NAG) at the end of the working shift. Then we assessed the correlation between exposure to hexavalent chromium and biological indicators.

Materials and Methods: This study involved 45 chrome platers (Cases) and 40 zinc platers (Controls) in Isfahan. Air and urine samples were collected at the end of the work shift. Measurement of Cr6 concentrations in the workers' breathing zone was performed using the NIOSH Methods 7600. Urine Cr levels were determined by atomic absorption spectrophotometry, with a graphite furnace (Shimadsu, AA680). B2M and NAG were measured by Kits.

Results: Overall, geometric mean of hexavalent chromium concentrations in the breathing zone was significantly higher among chrome platers (14.577 μg/m3) compared to zinc platers (0.862 μg/m3, p<0.001). Moreover, the mean urine Cr concentrations were higher in chrome platers (9.198 vs. 1.811 μg / g creatinine, p<0.001). Similarly, there were significant differences between mean NAG in chrome platers (12.608IU/gr creatinine) and zinc platers (6.824 IU/g creatinine, p<0.001). Differences in B2M concentrations were not significant (p>0.05). A significant correlation was found between Cr6 concentrations in the chrome platers' breathing zone and their urinary chromium levels (r= 0.838, p<0.001). A similar association was found between concentrations of Cr6 and NAG in the breathing zone (r= 0.304, p<0.05).

Conclusion: As urinary B2M concentration did not change significantly, it may not be a sensitive indicator in evaluating exposure to hexavalent chromium. There were significant differences between mean urinary Cr and NAG concentrations in the two groups. The significant correlations between Cr and NAG concentrations indicate that these markers may be suitable indicators of exposure to hexavalent chromium. Our results indicate that NAG is an early indicator of renal dysfunction in chrome platers.

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Background and Aim: Some medically important species of Muscidae and Fanniidae families are among synanthropic flies and can be seen in human habitats therefore they can be mechanical vectors of different pathogenic microorganisms. Identification and determination of species of these flies is essential for any control program planning. This study was conducted to determine the faunal diversity of Muscidae and Fanniidae flies in Tehran, Iran.

Methods and Materials: This was a cross-sectional descriptive and taxonomic study, conducted in 2 phases, during 1996-97 (pilot study) and 2000-2002 (complementary study) in Tehran and suburbs. Medically important flies were captured and identified. A net-hashing was used to capture adult flies by the direct observing method. To determine the fauna of flies in different habitats, 4 biotopes, including corpse (human, birds, livestock), garbage and decaying organic matter, animal carcasses, and human indoor habitat, were selected. Big hashing nets (95 cm in diameter) were used for capturing adult flies.

Results: A total of 2418 adult flies belonging to 8 families of Muscidae, Fanniidae, Calliphoridae, Sarcophagidae, Tachinidae, Syrphidae, Conopidae, and Anthomyiidae were captured. Among these, 1279 belonged to the Muscidae and Fanniidae families. Four genera and 5 medically important species were identified from two families.

Conclusion: Based on the existing scientific documentation, 2 species of M. stabulans and F. scalaris are reported for the first time from Iran. However, M. stabulans is a common species, the presence of which in Iran seemed probable.