Showing 4 results for Lethal Dose
Iman Zarei, Alireza Pourkhabbaz, Hossein Alipour, Sayyed Hossein Khazaei,
Volume 6, Issue 19 (1-2013)
Abstract
Background: The development of toxicity tests regarding toxic responses of different fish species could be more effectively used in predictive toxicology and risk assessment. In this study lethal concentrations (LC50-96 h) values of copper sulphate an important toxic industrial pollutant, on Capoeta fusca were determined. Behavioral changes at different concentrations of CuSO4 were determined for the C.fusca.
Methods: The sample fishes were collected from Qanat in Birjand and were transported to the laboratory in polythene bags. The exposure time of fish to CuSO4 was 96 hours. Mortalities were recorded at 24, 48, 72, and 96 hours of exposure, and the dead fish were removed regularly from the test aquariums. Physicochemical parameters, such as dissolved oxygen, pH and Total hardness of aquaria were monitored daily.
Results: The LC50 values for CuSO4 at 24, 48, 72, and 96 h of exposure, were 43.62, 12.6, 7.66, and 6.85 mg/L, respectively. The median LC50 value of CuSO4 for C.fusca was found to be 6.928 mg/L by EPA method and estimated to be 6.787 mg/L with SPSS statistical software.
Conclusion: The mortality decreased with time, and most of the deaths occurred during the first 24 h. In addition, behavioral changes increased with increased concentration. This metal is an important constituent in industrial effluents discharged into freshwaters. The results obtained in this study clearly revealed the fact that it is necessary to control the use of a heavy metal such as copper.
Saeed Zahedi, Hossein Vaezzade, Maryam Rafati, Musa Zarei Dangesaraki,
Volume 8, Issue 24 (4-2014)
Abstract
Background: Iron, manganese, and aluminum are three abundant metals on earth and their concentrations have increased in aquatic environments as a result of natural and industrial activities. This study was undertaken to report the median acute toxicity (LC50) and accumulation of the sub-lethal concentration (10% 96-h LC50) of iron (Fe), manganese (Mn) and aluminum (Al) in kutum (Rutilus kutum) fingerlings.
Methods: For the 96-h LC50, the fish were exposed to concentrations of 105, 111, 117, 123, 129 and 135 mg/l of Fe and 40, 45, 50, 55, 60, and 65 mg/l of Mn and 18, 22, 26, 30, 34 and 38 mg/l of aluminum for 4 days. For sublethal exposure, they were exposed to mediums with concentrations of 12.3, 5.4 and 2.9 for Fe, Mn, and aluminum, respectively. Metal concentrations were determined by atomic absorption spectrophotometry in the gill tissues.
Results: Probit analysis showed the 96-h LC50 values of 122.98, 54.39, and 28.89 mg/l for Fe, Mn, and aluminum, respectively. Sub-lethal tests were conducted with nominal concentrations of 12.3, 5.4, and 2.9 mg/l of Fe, Mn, and aluminum for four days, respectively. Significant accumulations were observed in gills for all tested metals as compared to the control groups in short-term exposure (P<0.05).
Conclusion: Obtained results clearly show that aluminum is the most toxic metal among tested ones for kutum fingerlings and it has the highest branchial AF value during sub-lethal exposure.
Ali Banagozar Mohammadi, Hamid Noshad, Ali Ostadi, Ali Reza Ghaffari, Maryam Zaare Nahandi, Ahad Banagozar Mohammadi,
Volume 9, Issue 28 (3-2015)
Abstract
Background: Acrylamide (C3H5NO) is a vinyl monomer. This water-soluble crystalline solid is a colorless, odorless agent which is used in scientific laboratories and some industries. Acrylamide has cellular oxidative effects. Acute or chronic poisoning with this agent happens as a result of skin, respiratory, or oral contacts. Clinical manifestations depend on the dose, duration, and frequency of contact. Management of these patients consists of conservative and palliative therapies to reduce the oxidative effects.
Case: The case was a 29-year-old girl with a Master of Sciences degree in genetics who worked in a university research center with previous history of depression. She had ingested 100cc of 30% Acrylamide solution for intentional suicide attempt. The patient was successfully managed using N-acetyl cysteine, vitamin C, and melatonin.
Conclusion: Early diagnosis and appropriate treatment with recommended agents together with supportive therapies can save the life of patients exposed to potentially lethal doses of acrylamide, although intentional or accidental.
Ali Sadeghi, Mohamad Reza Imanpoor,
Volume 9, Issue 29 (4-2015)
Abstract
Background: Since heavy metals can accumulate in the tissues of aquatic organisms, they can cause a range of hazardous effects which can become harmful to humans. The aim of this study was to investigate the acute effects of some heavy metals as potential dangerous substances by assessing the mortality effects of Mercuric Chloride (HgCl2), Lead Chloride (PbCl2) and Zinc Sulfate (ZnSO4) pollutants on a freshwater fish, silver dollar (Metynnis fasciatus).
Methods: Fish samples were exposed to different concentrations of mercuric chloride (HgCl2), lead chloride (Pbcl2) and zinc sulfate (ZnSO4) for 96h and their cumulative mortality was calculated in 24h intervals.Results were analyzed by SPSS 16 to obtain number of cumulative mortality and lethal concentrations (LC10-99).
Results: LC50-96h was 0.94±0.41ppm, 86.84±1.04ppm and 32.24±1.41ppm for mercuric chloride, lead chloride and zinc sulfate, respectively. So, mercury had the highest toxicity to silver dollar fish.
Conclusion: Mercuric chloride and lead chloride has the lowest and highest rate of mortality among these tree metals on silver dollar fish however, the mortality rate was increased with increasing concentrations of toxins with time.
