Determination of Median Lethal Concentration (LC50) and Nitrite Accumulation in the Blood and Tissue of Blood Cockle (Tegillarca granosa, Linnaeus 1758)

Human health risk of nitrate in groundwater of Tehran-Karaj plain, Iran

Groundwater pollution by nitrate has is a major concern in the Tehran-Karaj aquifer, Iran, where the wells provide up to 80% of the water supply for a population of more than 18 million-yet detailed human health risks associated with nitrate are unknown due to the lack of accessible data to adequately cover the aquifer in both place and time. Here, using a rich dataset measured annually in more than 75 wells, we mapped the non-carcinogenic risk of nitrate in the aquifer between 2007 and 2018, a window with the most extensive anthropogenic activities in this region. Nitrate concentration varied from ~ 6 to ~ 150 mg/L, around three times greater than the standard level for drinking use, i.e. 50 mg/L. Samples with a non-carcinogenic risk of nitrate, which mainly located in the eastern parts of the study region, threatened children's health, the most vulnerable age group, in almost all of the years during the study period. Our findings revealed that the number of samples with a positive risk of nitrate for adults decreased in the aquifer from 2007 (17 wells) to 2018 (6 wells). Although we hypothesized that unsustainable agricultural practices, the growing population, and increased industrial activities could have increased the nitrate level in the Tehran-Karaj aquifer, improved sanitation infrastructures helped to prevent the intensification of nitrate pollution in the aquifer during the study period. Our compilation of annually mapped non-carcinogenic risks of nitrate is beneficial for local authorities to understand the high-risk zones in the aquifer and for the formulation of policy actions to protect the human health of people who use groundwater for drinking and other purposes in this densely populated region.

Toxicity effect of Diuron on gill tissue structure and the tissue residue of blood cockles (Tegillarca granosa)

This study aimed to identify the toxicity effect of Diuron on Tegillarca granosa by determining accumulation in the soft tissues and alteration on the gill tissue structure. Wild stocks T. granosa were grouped to identify the initial Diuron concentration and 48-h exposure in different concentrations (0, 1, 2, 3, and 4 mg·L^-1). The Diuron in tissue was extracted using an established procedure and identified using High-Performance Liquid Chromatography (HPLC). Gills were analysed for histopathological study; tissue structure was classified and scored using a developed scoring system. Diuron concentration in the soft tissue of exposed T. granosa was in the range 1.27-8.09 mg·kg^-1, w/w and not proportionately increase along with the exposure concentration. The mean index values of the gill histopathology ranged from 5.25-7.67 and classified as moderate to severe. Gills characteristics and T. granosa protective behaviour potentially limit Diuron accumulation in the soft tissue.

Gaussian Distribution Model for Detecting Dangerous Operating Conditions in Industrial Fish Farming

The development of better monitoring technologies, the early combat of outbreaks, massive mortality, and promoting sustainability are challenges that the aquaculture industry still faces, and the development of solutions for this is an open problem. In this paper, focusing our attention on monitoring technologies as a promising solution to these issues, we report a Gaussian distribution model for detecting dangerous operating conditions in industrial fish farming. This approach allows us to indicate through a 2D image visualization when fish production is under normal, warning, or dangerous operating conditions. Furthermore, our proposed method has promising possibilities for application in the most varied fields of science, given that the mathematical procedure described allows us to discover the fundamental statistical structure of physical, chemical, and biological systems governed by laws of a probabilistic nature.