An extensive investigation on human risk associated with PAHs in fish and sediment in Bushehr, Northern of Persian Gulf.

Here, a comprehensive study was designed to estimate the human risk assessment attributed to exposure of polycyclic aromatic hydrocarbons (PAHs)in sediment and fish in most polluted shore area in north of Persian Gulf. To this end, a total of 20 sediment and inhabitual Fish, as one of most commercial fish, samples were randomly collected from 20 different stations along Bushehr Province coastline. The 16 different components of PAHs were extracted from sediment and edible parts of inhabitual fish and measured with high-performance liquid chromatography (HPLC) and gas chromatography (GC), respectively. In addition, dietary daily intake (DDI) values of PAHs via ingestion Indian halibut and the incremental lifetime cancer risk (ILCR) attributed to human exposure to sediments PAHs via (a) inhalation, (b) ingestion, and (c) dermal contact for two groups of ages: children (1-11 years) and adults (18-70 years) were estimated. The results indicated that all individual PAHs except for Benzo(b)flouranthene (BbF) and Benzo(ghi) perylene (BgP) were detected in different sediment sample throughout the study area with average concentration between 2.275 ± 4.993 mg.kg-1 dw. Furthermore, Naphthalene (Nap) with highest average concentration of 3.906 ± 3.039 mg.kg-1 dw was measured at the Indian halibut. In addition, the human risk analysis indicated that excess cancer risk (ECR) attributed to PAHs in sediment and fish in Asaluyeh with high industrial activities on oil and derivatives were higher the value recommended by USEPA (10-6). Therefore, a comprehensive analysis on spatial distribution and human risk assessment of PAHs in sediment and fish can improve the awareness on environmental threat in order to aid authorities and decision maker to find a sustainable solution.

Assessment of Polycyclic Aromatic Hydrocarbons (PAHs) in Seawater and Sediments, Human and Ecological Risks, Northern Coastline of Persian Gulf.

This study aimed to assess 13 PAHs concentrations and induced human and ecological risks in seawater and surficial sediments of eight estuaries in the northern coastline of the Persian Gulf, Iran, 2021. The range of Σ13 PAHs concentration was 0.24-8.83 µg L-l and 3.1-11.46 µg g-1 dry weight, and the mean value was 4.99 µg L-l and 6.06 µg g-1 dry weight in seawater and sediment, respectively. Two, three and four rings PAHs were dominant with 29.33% and 41.33% of ΣPAHs in seawater and sediment, respectively. The primary source of PAHs was both pyrolytic and petrogenic. Most PAHs' calculated health (DCR, HQs, TEF, MEF) and ecological risks (SQGs) values in seawater were in the moderate range or high-risk values for damage to the marine environment. It is concluded that the pollution of PAHs should be carefully considered, and the government should make a proper action plan to minimize the pollution.

Isolation, identification and reviewing the health effect of HPC bacteria in household point-of-use (PoU) water treatment devices: a case study, Ahvaz, Iran.

In Ahwaz, a city in west southern Iran, the majority of households are using Point of Use (PoU) water treatment units. The heterotrophic plate count (HPC) bacteria were isolated from these units while they were mounted on water distribution system in order to determine the variations in HPC and diversity of the bacterial population using polymerase chain reaction (PCR). Results showed that bacterial population regrowth in PoU units could increase HPC exceeding the limit of the 500 CFU/mL in outlet water. In around 70% of the input water samples, the HPC was less than 500 CFU/ml with a mean of 226.7 (CI 95%: 28.1-425.3). HPC in output treated water samples had an increasing trend from the start of the unit operation with a mean of 2416.4 (CI 95%: 1074.9-3757.9). Out of 49 detected bacterial strains, 20 strains were Gram-negative and 29 Gram-positive. Bacillus was the most frequent genes detected in inlet and outlet water samples. Most of the identified bacterial strains were opportunistic pathogens potentially dangerous for immunocompromised population. HPC population in PoU units significantly can be increased during a one-month period of operation, so replacement of the filters must be done regularly.

Spatio-temporal variations of airborne bacteria from the municipal wastewater treatment plant: a case study in Ahvaz, Iran.

The study of bioaerosol dispersion in wastewater treatment plants (WWTPs) has received considerable attention. This study aimed to investigate the seasonal changes and spatial distributions of airborne bacteria around different parts of Ahvaz WWTP, the capital city of Khuzestan Province, Iran, over 4 months in the cold and warm seasons. Samples were collected from 2 and 10-m intervals of grit chamber (GCh), primary sludge dewatering basin (PSDB), aeration tank (AT), as well as 60-m upstream (US) and downstream (DS) of the WWTP. Further, bacteria in the indoor air of administrative building (AB) of WWTP were investigated. Bioaerosols were collected by passive sampling method. The total bacteria count was 105.3 ± 98.5 CFU/plate/h. The dominant bacteria stood 2 m away from the AT with an average 244.2 ± 73.1 CFU/plate/h in the warm season while they were the lowest with an average 43 ± 11.4 CFU/plate/h in the 10-m distance of the GCh in the cold season. According to the sequencing results, the dominant bacterial species included Bacillus pumilus (26.7%), Staphylococcus arlettae (23.2%), Kocuria turfanensis (13.6%) and Alicycliphilus (9.2%), respectively. There was a positive relationship between the release of bacteria, temperature and wind speed. However, there was a significant negative correlation between total bacteria concentration and humidity. There are accumulative perils to WWTP workers and neighbors exposed by persistent exposure to airborne bacteria. Therefore, AT should be paid more attention as a dominant source of airborne bacteria emissions, especially in the warm season.

Heavy metals risk assessment in fish species (Johnius Belangerii (C) and Cynoglossus Arel) in Musa Estuary, Persian Gulf.

In this study the possible health effects of consumption of benthopelagic (Johnius Belangerii (C); JB) and demersal (Cynoglossus Arel; CA) fishes were evaluated. These fish species living in the Musa estuary (the biggest estuary in the south of Iran and in the northern coastline of Persian Gulf) are likely to be polluted with Hg, V, Ni and Tl. The food frequency questionnaire (FFQ) was used to estimate fish intakes in the residents of Mahshahr city. Also, heavy metal concentrations were determined in fishes and compared with the maximum permissible levels (MPLs). The bioaccumulation factor (BAF) showed high bioaccumulation ability for Hg and Tl in both fish spices. The ratio of TDI/EDI showed the importance of the health hazard by both fish consumption. Also, Hg and Tl in fishes had a higher calculated target hazard quotient (THQ) than the limits. Regarding with the high possibility of serious health concerns associated with Hg and Tl contamination in the Musa estuary, it is suggested to do appropriate and urgent actions by the governors.

Determination of nickel and thallium concentration in Cynoglossus arel fish in Musa estuary, Persian Gulf, Iran.

Heavy metals with high bioaccumulation capacity are considered as important contaminants and may be available in high concentrations in environment and biota samples. The main aim of this study was to determine the concentration of nickel and thallium in Cynoglossus arel fish in Musa estuary. Sixty-seven fish samples were collected from Musa estuary during five intervals of 15 days in summer 2013. After biometric measurements, the concentrations of nickel and thallium were measured by graphite furnace atomic absorption spectrophotometer. The mean concentration of nickel and thallium in muscle tissue of fish samples was 2.458 ± 0.910 and 0.781 ± 1.754 mg kg-1/ww, respectively. The GLM analysis showed a significant negative relationship between nickel concentration and length. In addition, there was a significant positive relationship between thallium concentration and fish length. Nickel concentration exceeded the allowable standards of WHO and FDA in Cynoglossus arel. Therefore, regarding with high consumption of seafood in this region, it is recommended that these fishes should be consumed under a nutritionist counseling.