Showing papers by "Hassan Nasirian published in 2016"

Assessment of bed sediment metal contamination in the Shadegan and Hawr Al Azim wetlands, Iran.

Abstract: The Shadegan and Hawr Al Azim wetlands are important natural resources in southwestern Iran, yet relatively little work has been done to assess ecosystem health of the wetlands. Bed sediment from both wetlands was sampled in individual months between October, 2011 and December, 2012 and analyzed for As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Pb, and Zn using inductively coupled plasma optical emission spectrometry (ICP-OES). The metals data were evaluated using a combination of sediment quality guidelines from the Ontario Ministry of Energy and Environment (MOEE, Canada), enrichment factors (EFs), and a geo-accumulation index (Igeo) approach. The sediments exceeded MOEE Lowest Effect Levels (LELs) consistently for Cr and Cu and a small proportion of samples (5%) for Hg. Levels of As, Cd, Fe, Pb, and Zn did not exceed LELs and none of the samples exceeded the Severe Effect Levels (SELs). In addition to the sediment guidelines, both the EF and Igeo calculations suggested levels of Mn and Fe were severely enriched, while the EF indicated Cd was slightly enriched. Metal levels in the Shadegan wetland exhibited both spatial and seasonal trends. Metal levels were greater near input areas from agricultural, urban, and industrial discharges and runoff as compared to the more remote and quiescent central part of the wetland. Except for Fe, the metal levels were greater in the wet season as compared to the dry season, perhaps due to greater stormwater runoff and sediment loads. This study provides baseline data which can be used to support development of appropriate contaminant source management strategies to help ensure conservation of these valuable wetland resources.

Toxicity of Cypermethrin and Chlorpyrifos Against German Cockroach [ Blattella germanica (Blattaria: Blattellidae)] Strains from Hamadan, Iran.

Abstract: Background German cockroach has relatively short life cycle and reproduce rapidly. It is the most common medically and public health pest. As a result, it is essential to combat this pest. Cypermethrin and chlorpyrifos are used by private companies in Hamadan to control Blattella germanica. It seems necessary to determine its susceptibility levels to these insecticides. Objective The aim of this study was to determine the susceptibility levels of B. germanica strains to cypermethrin and chlorpyrifos in Hamadan. Materials and methods In this study, the German cockroach strains were collected from two hospitals (Fatemiyeh and Atiyeh) in Hamadan and transfered to the insectarium. The cockroach strains were reared under the same laboratory condition. Then their sensitivity levels were considered to 1, 2, 4, 8 and 16 mg m -2 for cypermethrin and 0.82, 1.65, 3.31, 6.63, 9.945 and 13.26 mg m -2 for chlorpyrifos using surface contact method. Results Results based on insecticide treated doses, B. germanica strains showed different percent mortality to the insecticides ranged from 13.3-100. The LD 50 and LD 90 and regression lines of the treated insecticides against German cockroach strains indicate that Fatemiyeh Hospital strain is more susceptible to the treated insecticides than Atiyeh Hospital strain. The LD 50 and LD 90 of chlorpyrifos are also lower than cypermethrin, indicated that chlorpyrifos is more effective than cypermethrin against German cockroach. As the slopes of the regression lines are observed mild in this study indicate that the population of the cockroach strains is very heterogeneous. It can be a symbol of insecticides resistance to cypermethrin and chlorpyrifos. Conclusion As chlorpyrifos and cypermethrin insecticides are also used for residual spraying by private companies and the doses which provide more than 90% mortality are below the WHO recommended insecticide doses. Therefore, chlorpyrifos and cypermethrin insecticides can be used for B. germanica control in Hamadan within regular monitoring and preventive measures of resistance.

New aspects about Supella longipalpa (Blattaria: Blattellidae)

Abstract: The brown-banded cockroach, Supella longipalpa (Blattaria: Blattellidae) ( S. longipalpa ), recently has infested the buildings and hospitals in wide areas of Iran, and this review was prepared to identify current knowledge and knowledge gaps about the brown-banded cockroach. Scientific reports and peer-reviewed papers concerning S. longipalpa and relevant topics were collected and synthesized with the objective of learning more about health-related impacts and possible management of S. longipalpa in Iran. Like the German cockroach, the brown-banded cockroach is a known vector for food-borne diseases and drug resistant bacteria, contaminated by infectious disease agents, involved in human intestinal parasites and is the intermediate host of Trichospirura leptostoma and Moniliformis moniliformis . Because its habitat is widespread, distributed throughout different areas of homes and buildings, it is difficult to control. Considering its possible resistance to insecticides, the control situation may be far more complex. For improved control of S. longipalpa an integrated pest management program is needed. Sanitation, indoor insecticide spraying in the initial cockroach control phase and insecticide formulation baits are recommended simultaneously.

Tick-borne relapsing fever in Sabzevar (Khorasan Razavy Province), North-Eastern Iran

Abstract: Background: Soft ticks play an important role in transmission of bacteria, rikettsia and viral diseases to human. In Iran soft ticks of the genus Ornithodoros spread the tick-borne diseases. Objective: Present study was performed to investigate the latest situation of tick-borne relapsing fever (TBRF) among people and tick infectivity to Borrelia in Sabzevar, an endemic tick-borne relapsing fever region in Iran. Methodology: Ticks were collected in the sampled areas of Sabzevar County by clustered random sampling. The suspected cases of TBRF were passively detected in the study villages. Each of Ornitodoros tholozani was separately crushed and resultant homogenate was inoculated intraperitoneally into a white mouse. Results: A total of 3892 soft ticks were collected and identified. The Argas and Ornitodoros genus were observed 69.6 % and 30.4 %, respectively. Argas persicus, Ornitodoros lahorensis, O. tholozani and A. reflexus species were found 68.0 %, 25.6 %, 4.8% and 1.6 %, respectively. A. persicus (68.0 %) and A. reflexus were found as the highest and the lowest frequent species. Totally 5.2 % of O. tholozani ticks infected with Borrelia persica. Among individuals who suspected to the TBRF, 5 cases infected with B. persica. Conclusions: The vector infectivity rates were 5.2 % which can be an important factor and ability to make proper decide decision for better TBRF management and revision of control measures. Also this study raises our country TBRF epidemiological aspects and improves them. Bangladesh Journal of Medical Science Vol.15(4) 2016 p.551-555