Quantitative microbial risk assessment of gastrointestinal illness due to recreational exposure to E. coli and enterococci on the southern coasts of the Caspian Sea.

Background: Gastrointestinal illness refers to a broad range of diseases that affect the digestive system, including infections caused by bacteria, viruses, and parasites. Quantitative Microbial Risk Assessment (QMRA) is a powerful tool used to evaluate the risks associated with microbial pathogens in various environments. The main objective of this study was to conduct a quantitative assessment of gastrointestinal illnesses that occur as a result of exposure to E. coli and enterococci during recreational activities on the southern coasts of the Caspian Sea. Methods: Samples were collected from the recreational beaches along the border line of the Caspian Sea. The samples were analyzed for the presence and enumeration of E. coli and enterococci using the microplate method and membrane filtration techniques. Then, the annual and daily infection risks were computed using the Monte Carlo simulation approach. Results: The results revealed that the risk of daily and annual infections on the coasts of Babolsar was higher than that on the coasts of Sari. Also, in the recreational waters of these beaches, the risk of infection by enterococci was higher than that posed by E. coli. In Babolsar, the average annual infection risk caused by E. coli and enterococci was 0.365 and 1 for children and 0.181 and 0.986 for adults. Also, in Sari, the average annual infection risk caused by E. coli and enterococci was 0.060 and 0.908 for children and 0.027 and 0.815 for adults. In addition, children were more likely than adults to become infected. Conclusion: In light of the study's findings, due to the entry of untreated urban wastewater into the southern part of the Caspian Sea (northern Iran) and the high risk of infectious diseases for children, more control and health measures are necessary for children's swimming.

Non-coding RNAs: A new frontier in benzene-mediated toxicity.

One of the most frequent environmental contaminants, benzene is still widely used as an industrial solvent around the world, especially in developing nations, posing a serious occupational risk. While the processes behind the toxicity of benzene grounds are not fully understood, it is generally accepted that its metabolism, which involves one or more reactive metabolites, is crucial to its toxicity. In order to evaluate the many ways that benzene could influence gene regulation and thus have an impact on human health, new methodologies have been created. The pathophysiology of the disorder may result from epigenetic reprogramming caused by exposure to benzene, including changes in non-coding RNA (ncRNA) markers, according to recent studies. We are interested in the identification of hazardous regulatory ncRNAs, the identification of these ncRNAs' targets, and the comprehension of the significance of these interactions in the mechanisms behind benzene toxicity. Hence, the focus of recent research is on long non-coding RNAs (lncRNAs), circular RNAs (circRNAs) and microRNAs (miRNAs), and some of the more pertinent articles are also discussed.

Global review, meta-analysis and health risk assessment of Polycyclic Aromatic Hydrocarbons (PAHs) in chicken kebab using Monte Carlo simulation method.

The primary concern with Polycyclic Aromatic Hydrocarbons (PAHs) is their harmful effects on health, including the risk of causing cancer. This study aimed to investigate the occurrence and concentration of 16 priority PAHs (PAH16) in chicken kebabs using a systematic review approach with meta-analysis. Additionally, the study estimated the possible risk assessment of the potential carcinogenic and non-carcinogenic effects of PAHs on consumers of chicken kebabs using the Monte Carlo simulation (MCS) method. The researchers collected data on the concentration of PAHs in chicken kebabs (grilled, smoked, roasted, or barbecued) from 99 original articles searched in the Web of Science, PubMed, Scopus, Science Direct, and Google Scholar databases from 2012 to April 2022. The concentration of PAHs was then analyzed using meta-analysis, and the Monte Carlo simulation (MCS) was used to evaluate the associated human health risks. The analysis showed that 68.6%, 21.1%, 7.1%, and 3.2% of chicken kebabs were prepared by grilling, smoking, barbecuing, and roasting, respectively. The meta-analysis and health risk assessment indicated that the mean values of HQ (hazard quotient) in Bap, Ace, Acy, Pyr, Flt, Flr, Nap, and Ant PAHs were 1.64, 1.38 × 10^-2, 1.10 × 10^-1, 1.09 × 10^-1, 2.55 × 10^-2, 1.60 × 10^-1, 8.13 × 10^-1, and 6.20 × 10^-3, respectively. Additionally, the mean values of LTCR (Incremental Lifetime Cancer Risk) in Bap, Ace, Acy, Pyr, Flt, Flr, Nap, and Ant were 4.85 × 10^-10, 8.06 × 10^-13, 6.65 × 10^-12, 3.23 × 10^-12, 1.01 × 10^-12, 6.38 × 10^-12, 1.62 × 10^-11, and 6.20 × 10^-3, respectively. The consumption of chicken kebabs prepared by barbecuing was found to be associated with an increased risk of cancer due to the formation of carcinogenic compounds, including benzo[a]pyrene (BaP). However, the non-cancer risk ratio of consuming grilled chicken other than BaP was found to be less than 1 (HQ < 1), indicating that there is no risk of carcinogenesis caused by PAHs from the consumption of chicken kebabs worldwide. The calculated values of the LTCR caused by PAHs in the consumption of chicken kebab throughout life were compared to the maximum acceptable risk value suggested by the EPA, which in the strictest case equals one cancer case per 10,000 people. The results indicate that there is no risk of carcinogenesis caused by PAHs due to the consumption of chicken kebab worldwide.

Carcinogenic and non-carcinogenic risk assessment of exposure to trace elements in groundwater resources of Sari city, Iran.

The daily intake of trace elements through water resources and their adverse health effects is a critical issue. The purpose of this research was to assess the carcinogenic and non-carcinogenic risks of exposure to iron (Fe), copper (Cu), manganese (Mn), zinc (Zn), chromium (Cr), lead (Pb), and arsenic (As) in groundwater resources of Sari city, Iran. The concentrations of the trace elements in a total number of 66 samples from the groundwater sources were measured using inductively coupled plasma mass spectrometry (ICP-MS). The hazard index (HI) levels of exposure to the trace elements from the groundwater sources for adults, teenagers, and children were 0.65, 0.83, and 1.08, respectively. The carcinogenic risk values of Cr and As in the groundwater sources for children, teenagers, and adults were 0.0001, 0.00009, 0.00007, 0.0003, 0.0002, and 0.0001, respectively, causing a total carcinogenic risk value higher than the acceptable range, and removing Cr and As from the groundwater resources is recommended for safe community water supply.

Health risk assessment of swimming beaches microbial contamination: a case study - Mahmoudabad, Iran.

Waterborne organisms in marine water generally originate from untreated wastewater discharged into the sea. The presence of numerous leisure beaches in Mahmoudabad city, Iran, annually attracts thousands of tourists from all over the country to participate in recreational swimming activities. This study probabilistically characterized the health risks associated with recreational swimming engendered by waterborne pathogens, such as intestinal enterococci and Escherichia coli (E. coli) at 15 sampling points along the beaches of the study using quantitative microbial risk assessment (QMRA). The mean annual infection risk of E. coli in children and adults was 0.424 and 0.229, respectively. The respective risk in terms of enterococci was 0.999 and 0.997, which were higher than the level recommended by the WHO and EPA. The results show that the risk of infection for children was higher than adults. Related authorities have to consider measures to improve environmental quality to protect tourists' and residents' well-being.

Comparing the efficiency of unmodified dried sludge adsorbents and those modified via chemical and microwave methods in removing 2,4-dinitrophenol from aqueous solutions.

2,4-dinitrophenol (DNP) is found in small amounts in the effluent of many wastewater treatment plants. The contamination of drinking water with this pollutant, even in trace amounts, causes toxicity, health problems, and unfavorable taste and odor. This study aims to compare the efficiency of non-modified and modified dried sludge adsorbents in removing 2,4 DNP from aqueous solutions. The results of 2,4DNP removal by high-performance liquid chromatography method at the wavelength of 360 nm in a batch mode were obtained by changing the influential factors including contact time, pH, initial concentration of the contaminant, and adsorbent dosage. Eventually, the results were analyzed by kinetic and isotherm models. In this research, the optimal time was obtained as 60 min and pH as seven for all three adsorbents. The results showed that the removal percentage increases by rising adsorbent dosage and reducing contaminant concentration. The correlation coefficient value of linear and non-linear led that in kinetic studies, it follows the pseudo-second order model. In contrast, in isotherm studies, examining linear and non-linear models of isotherms showed that the data for every three types of adsorbents follow the Freundlich model well. The adsorption process is highly dependent on pH and affects the adsorbent surface properties, ionization degree, and removal percentage. At high pH, hydroxide ions (OH) compete with 2,4 DNP molecules for the adsorption sites. The adsorption occurs quickly and gradually reaches a constant value because, over time, the adsorption sites are occupied until reaching a saturated limit. By increasing the adsorbent dosage, the adsorption percentage increased significantly, which is due to the fact that higher amounts of adsorbent cause more adsorption sites.