Influence of chlorpyrifos and endosulfan and their metabolites on the virulence of Helicobacter pylori

Organochlorine (OC) and organophosphorus (OP) pesticides such as chlorpyrifos (CPF) and endosulfan (ES) have been associated with a plethora of adverse health effects. Helicobacter pylori (H. pylori) infection can lead to gastrointestinal diseases by regulating several cellular processes. Thus, the current study focuses on the effect of the co-exposure to pesticides and H. pylori on gastric epithelial cells. We have used the in-silico approach to determine the interactive potential of pesticides and their metabolites with H. pylori-associated proteins. Further, various in-vitro methods depict the potential of ES in enhancing the virulence of H. pylori. Our results showed that ES along with H. pylori affects the mitochondrial dynamics, increases the transcript expression of mitochondrial fission genes, and lowers the mitochondrial membrane potential and biomass. They also promote inflammation and lower oxidative stress as predicted by ROS levels. Furthermore, co-exposure induces the multi-nucleated cells in gastric epithelial cells. In addition, ES along with H. pylori infection follows the extrinsic pathway for apoptotic signaling. H. pylori leads to the NF-κB activation which in turn advances the β-catenin expression. The expression was further enhanced in the co-exposure condition and even more prominent in co-exposure with ES-conditioned media. Thus, our study demonstrated that pesticide and their metabolites enhance the pathogenicity of H. pylori infection.

Pesticide applicators and cancer: a systematic review

The objective of the study was to identify and analyse the research done on the occurrence of cancer among pesticide applicators by conducting a systematic review of the scientific literature. PRISMA Guidelines was followed to conduct the study. Search was done in Scopus, PubMed, Embase, MEDLINE and Google Scholar databases with search terms "PESTICIDE APPLICATORS", "CANCER" using Boolean operator "AND". Meta-analysis and review articles were excluded from the study. A total of 32 studies were identified among which the average sample size was found to be 60,521. Increased RRs/ORs and positive exposure-response relationships were observed for 31 pesticides. Organophosphate and organochlorine classes of pesticides were the most to be associated with cancer. Lung cancer was observed the most followed by prostate, multiple myeloma and colon cancers among pesticide applicators. It was concluded that there is an increased risk of cancer among the pesticide applicators, whereby which bringing into focus the need to educate and train the workers on following adequate safety measures and making them aware of the hazardous chemicals. Further evaluation on the carcinogenicity of pesticides is also required.

Occurrence and source apportionment of polycyclic aromatic hydrocarbons (PAHs) in dust of an emerging industrial city in Iran: implications for human health

Polycyclic aromatic hydrocarbons (PAHs) bounded to street dust are a severe environmental and human health danger. This study provides preliminary information on the abundance of PAHs in street dust from Rafsanjan city, Iran, where industrial emissions are high and data are lacking. Seventy street dust samples were collected from streets with different traffic loads. The United States Environmental Protection Agency (USEPA) Standard Methods 8270D and 3550C were used for the measurement of PAHs using GC mass spectroscopy. The total concentration of PAHs was 1443 ng g-1, with a range of 1380-1550 ng g-1. Additionally, the concentration of carcinogenic PAHs (∑carcPAHs) ranged from 729.5 to 889.4 ng g-1, with a mean value of 798.1 ng g-1. Pyrene was the most abundant PAH, with an average concentration of 257 ng g-1. Source identification analyses showed that vehicle emissions along with incomplete combustion and petroleum were the main sources of PAHs. The ecological risk status of the studied area was moderate. Spatial distribution mapping revealed that the streets around the city center and oil company had higher PAH levels than the other sectors of Rafsanjan. The results indicated that dermal contact and ingestion of contaminated particles were the most important pathways compared to inhalation. The mean incremental lifetime cancer risk (ILCR) was 1.4 × 10-3 and 1.3 × 10-3 for children and adults, respectively. This implies potentially adverse health effects in exposed individuals. The mutagenic risk for both subpopulations was approximately 18 times greater than the one recommended by USEPA. Our findings suggest that children are subjected to a higher carcinogenic and mutagenic risk of PAHs, especially dibenzo[a,h]anthracene (DahA), bounded to street dust of Rafsanjan. Our study highlights the need for the development of emission monitoring and control scenarios.

Evolution of human health risk based on EPA modeling for adults and children and pollution level of potentially toxic metals in Rafsanjan road dust: a case study in a semi-arid region, Iran

Humans can be directly exposed to potentially toxic metals in the urban environment via inhalation, ingestion, or dermal contact of dust particles. This paper focuses on human health risk assessment of urban dust contaminated with potentially toxic metals. The levels, sources, and human health risks of nine potentially toxic metals (i.e., As, Cd, Cu, Cr, Ni, Pb, Co, Mn, and Zn) in 200 road dust samples from Rafsanjan area were investigated. Pollution level was assessed using the pollution index (PI) and geoaccumulation index (I_geo), and the health risk assessment was performed following the methodology described by the US Environmental Protection Agency. The mean concentrations of As, Cu, Pb, Cd, Cr, Ni, Zn, Co, and Mn in road dust were 105.3 ± 5.7, 791.4 ± 29.8, 123.1 ± 9.7, 28.4 ± 3.3, 3.1 ± 0.6, 18.4 ± 1.6, 252.6 ± 8.3, 16.5 ± 1.4, and 525.9 ± 21.0 mg kg^-1, respectively. Thus, the concentrations of potentially toxic metals in road dust were higher than their corresponding natural background values, indicating that all studied potentially toxic metals were impacted by anthropogenic activities. The results of the current study are comparable to other studies conducted on road dust in other cities worldwide. Both of I_geo and PI decreased following order Cu > Mn > Pb > As > Zn > Cd > Ni > Cr > Co. Health risk assessment indicated that both of children and adults could be exposed to a potential increased risk of developing cancer over a lifetime from exposure to arsenic through ingestion of the dust samples. However, Pb ingestion can increase cancer risk in children.