Analysis of Root Cause of the Fatal Occupational Accidents in a Gas Refinery Using the Tripod-Beta Method

Introduction: Most critical accidents in different industries are observable, but their severity is also predictable and can be controlled. Provided that accident analysis is properly managed with a preventive approach and based on correct findings, in a principled and realistic manner, root causes, corrective actions, and safety measures regarding accidents are performed. Material and Methods: The present research was a descriptive-analytic study, and the reported and recorded fatal occupational accidents were analyzed in the onshore section of one of the construction refinery projects in the South Pars Gas Refinery over a decade using the Tripod Beta method and then main risk factors, pre-conditions, and underlying causes, as well as the existing protective barriers, were identified, and an accidents tree was drawn. Results: The analysis of fatal occupational accidents showed that 26 immediate causes, 39 preconditions, and 50 underlying causes were involved in those accidents. Six key risk factors include lack of responsibility/organizational impact (57.8%), training (22.2%), hardware or tools and equipment (6.7%), maintenance management (6.7%), work procedures (4.4%), and Error Enforcing conditions (2.2%) had the largest share of the occurrence of accidents.  Conclusion: More than 80% of fatal occupational accidents can be controlled by modifying the two main factors, responsibility and organization and training. Therefore, implementing the total productive maintenance method, effective monitoring of staff work, hiring staff with sufficient knowledge and skills, and improving training indicators will increase understanding of hazard sources, improve safety and reduce accidents.

Mercury levels in avian feathers from different trophic levels of eight families collected from the northern region of Iran

Mercury levels were determined in feathers from 83 birds belonging to 18 species (eight families), all collected from the northern region of Iran. Mercury levels were evaluated in relation to taxonomic affiliation and feeding strategies. Mercury levels in the feathers were between 0.05 ± 0.01 and 1.10 ± 0.15 μg g(-1) dry weight, and there was a significant effect of taxonomic groups (p < 0.05). The highest mercury levels were found in Accipitridae, and mercury was not detected in the family Upupidae. The pattern for mercury levels was Accipitridae > Pelecanidae > Sternidae > Ardeidae > Anatidae > Rallidae > Phasianidae (p < 0.05). Significant differences (p < 0.05) in the mean mercury levels were found among species as a function of feeding method and trophic level. Mercury levels were highest in the carnivorous species and lowest in the herbivorous species. Mercury levels in feathers of birds in this study were generally below the thresholds reported to affect reproduction.

Distribution and composition pattern of polycyclic aromatic hydrocarbons in different tissues of sturgeons collected from Iranian coastline of the Caspian Sea

The levels of 16 polycyclic aromatic hydrocarbons (PAHs) were determined in the liver, kidney, gills and muscle tissues of Persian sturgeon (Acipenser persicus; n=16), and Stellate sturgeon (Acipenser stellatus; n=7) collected from coastal waters of the South Caspian Sea from March and April 2011. The distribution and composition pattern of PAHs in the different tissues of sturgeons, and the effects of lipid content in sturgeon tissues and the octanol-water partition coefficient (Kow) of PAHs congeners on them were analyzed. The levels of total PAHs in the various tissues of Persian sturgeon and Stellate sturgeon ranged from 2.095 to 6.587 and 1.942 to 6.206 μg g(-1)dw, respectively. Stellate sturgeon showed significantly higher levels of heavy PAHs (⩾ 4-rings) than Persian sturgeon. The analysis has revealed a high degree of differential accumulation of the studied PAHs in the tissues of the both species. Low molecular weight PAHs predominated in the sturgeons, accounting for 81.89% of the total PAHs. Among the sixteen tested PAHs, naphthalene was the most dominant congener, followed by phenanthrene and fluorene. The PAHs levels and distribution in the tissues of sturgeons are dependent on both the Kow of PAH congeners and the lipid content in these tissues. There was a significant positive relationship (r=0.868, p<0.005) between lipid content and PAHs levels. The statistically significant negative relationships (p<0.01) were found between log Kow and log-transformed PAHs levels for muscle tissues of both sturgeon species.

Assessment trace elements concentrations in tissues in Caspian Pond Turtle (Mauremys caspica) from Golestan province, Iran

Concentrations of cadmium, lead, zinc, and copper were measured in different organs and tissues of 15 Caspian Pond Turtle (Mauremys caspica) collected from Gharehsu River, Golestan province, Iran in June and July 2012. Mean concentrations (dry weight) of zinc and copper were 66.9 and 6.7µgg(-1) in liver, 147 and 3.4µgg(-1) in heart, 93.2 and 4.9µgg(-1) in shell, and finally 150.7 and 4.5µgg(-1) in muscle, respectively. Mean concentrations of cadmium and lead were 5.8 and 32.4µgg(-1) in liver, 2.9 and 20.9µgg(-1) in heart, 3.5 and 21.5µgg(-1) in shell, and finally 2.5 and 27.5µgg(-1) in muscle, respectively. On average, lead, cadmium, copper and zinc concentrations in the analyzed tissues were much higher than those reported in other freshwater turtle species. In particular, the mean concentrations of lead in liver and muscle of Caspian Pond Turtle was extremely high. To our knowledge, this is the first report into metal accumulation in tissues and organs of Caspian Pond Turtle from of the Gharehsu River in Golestan province, Iran.

Bioaccumulation of Cd, Pb and Zn in the edible and inedible tissues of three sturgeon species in the Iranian coastline of the Caspian Sea

The accumulations of Cd, Pb and Zn were determined in edible and inedible tissues of Persian sturgeon (Acipenser persicus; n=27), stellate sturgeon (Acipenser stellatus; n=5) and beluga (Huso huso; n=4) collected from coastal waters of the South Caspian Sea from March to April 2011. Concentrations of metals evaluated in the caviar, muscle, liver, kidney, gills, ovary and heart of the three species of sturgeons have been assessed using the flame and graphite furnace atomic absorption spectrophotometer. Concentrations of Zn, Pb and Cd in the edible and inedible tissues were apparently different among the three species of sturgeons. Especially, beluga heart showed the highest concentrations of Zn and Pb and Cd in Persian sturgeon liver. The analyzed metals were found in the caviar and muscle samples of Persian sturgeon and likewise muscle samples two other sturgeon species at mean concentrations under the permissible limits proposed by MAFF (2000).

Bioaccumulation of Zn, Cu and Mn in the caviar and muscle of Persian sturgeon (Acipenser persicus) from the Caspian Sea, Iran

Concentrations of Zn, Cu and Mn were examined in caviar and muscle of the Persian sturgeon (Acipenser persicus) collected from coastal waters of south Caspian Sea during March and April, 2011. Mean Zn, Cu and Mn concentrations in caviar samples were 21.48, 2.05 and 1.66 μg g(-1) wet weight basis, respectively. The mean Zn, Cu and Mn concentrations in muscle tissues were 7.49, 1.00 and 0.34 μg g(-1) wet weight basis, respectively. The mean concentrations of Zn and Cu in caviar and muscle samples were under the permissible limits proposed by the United Kingdom's Ministry of Agriculture, Fisheries and Food (2000).