Advances in Forensic Geochemistry

This chapter is meant to give the state of the art of forensic geochemistry and recent advances. In terms of forensic organic geochemistry, detecting mature organic matter including polluting hydrocarbons follows an experimental procedure by using recent experimental analytical techniques. However, the interpretation of these results needs an understanding of the geochemical context to make a distinction between the natural and the human made origin of oil. Infrared data coupled with statistical analyses would have an important relevance for the detection of the pollution during the Anthropocene, which is marked an increasing human pollution reaching the level of environmental crimes. In terms of nuclear and isotopic forensic geochemistry, recent studies provided that nuclear forensics considers the fact that some measurable parameters or signatures are distinctive.

Bioaccumulation of Heavy Metals in Pelagic and Benthic Fishes of Ogbese River, Ondo State, South-Western Nigeria

The bioaccumulation factors (BAFs) of heavy metal (Fe, Zn, Pb, Cd, Cr, Cu, Mn, and As) concentrations in benthic and pelagic fish organs (muscles, gills, liver, and hearts), and concentrations of heavy metals in water and sediments of Ogbese River, Ondo State, Nigeria were investigated. From the results, the concentrations of heavy metals in the water were within the permissible limits stipulated by the World Health Organization (WHO). However, in the sediments, Cd, Cr, Fe, and Mn concentrations were higher than the limits, while Zn, As, Pb, and Cu were within limits. Heavy metals concentrations in the fish organs showed that all fish species were within the permissible limits implying no contamination. More so, the BAFs in all fish organs revealed no probability of accumulation while the geoaccumulation index and contamination factor showed no contamination to moderate contamination. The potential ecological risk index also showed moderate risk factor indicating that the water and sediments were not extremely polluted for higher organisms but may be toxic for lower ones. The study concludes that constant monitoring and study should be conducted by researchers and the Ministry of Water Resource and that the community should be aware of the danger human pollution can cause to the river.

How the AHR Became Important in Cancer: The Role of Chronically Active AHR in Cancer Aggression

For decades, the aryl hydrocarbon receptor (AHR) was studied for its role in environmental chemical toxicity i.e., as a quirk of nature and a mediator of unintended consequences of human pollution. During that period, it was not certain that the AHR had a “normal” physiological function. However, the ongoing accumulation of data from an ever-expanding variety of studies on cancer, cancer immunity, autoimmunity, organ development, and other areas bears witness to a staggering array of AHR-controlled normal and pathological activities. The objective of this review is to discuss how the AHR has gone from a likely contributor to genotoxic environmental carcinogen-induced cancer to a master regulator of malignant cell progression and cancer aggression. Particular focus is placed on the association between AHR activity and poor cancer outcomes, feedback loops that control chronic AHR activity in cancer, and the role of chronically active AHR in driving cancer cell invasion, migration, cancer stem cell characteristics, and survival.

Drug repurposing: cost effectiveness and impact on emerging and neglected diseases

Historically, pressure on nature brought about by ever-increasing human pollution and technological advancement culminate in emergence and re- emergence of infectious and non-infectious diseases; necessitating medications and drug discovery and development. The emergence of resistantmicroorganisms and the emergence of new infections disease conditions necessitate the production of entirely new drugs or modification of the existing ones to increase their efficacy. The development of novel medications is a very long and expensive process. There is a significant decrease observed in the number of new drugs approved for clinical use in recent years showing inconsistency in the face of scientific advances and research and development investment. Regardless of high investment and enormous contributions, very few molecules showed promising results. However, finding novel indications for existing drugs can be a useful method of reducing the developmental cycle of drugs. Repositioning (also called repurposing) has been described as the practice of developing new therapeutic uses for drugs, abandoned or drugs in development process, other than the initially intended or approved uses, except for the circumstances in which the novel use is comparable to the original indication with dissimilar pharmacological targets. This review aimed at looking into some of the available methods in drug repurposing. Key words: Drug discovery; Drug repurposing; Machine learning; Neglected Tropical diseases; Orphan drugs

Solving the Multi-Depot Green Vehicle Routing Problem by a Hybrid Evolutionary Algorithm

The growing concerns about human pollution has motivated practitioners and researchers to focus on the environmental and social impacts of logistics and supply chains. In this paper, we consider the environmental impact of carbon dioxide emission on a vehicle routing problem with multiple depots. We present a hybrid evolutionary algorithm (HEA) to tackle it by combining a variable neighborhood search and an evolutionary algorithm. The proposed hybrid evolutionary algorithm includes several distinct features such as multiple neighborhood operators, a route-based crossover operator, and a distance- and quality-based population updating strategy. The results from our numerical experiments confirm the effectiveness and superiority of the proposed HEA in comparison with the best-performing methods in the literature and the public exact optimization solver CPLEX. Furthermore, an important aspect of the HEA is studied to assess its effect on the performance of the HEA.

Human pollution exposure correlates with accelerated ultrastructural degradation of hair fibers

Exposure to pollution is a known risk factor for human health. While correlative studies between exposure to pollutants such as polycyclic aromatic hydrocarbons (PAHs) and human health exist, and while in vitro studies help to establish a causative connection, in vivo comparisons of exposed and nonexposed human tissue are scarce. Here, we use human hair as a model matrix to study the correlation of PAH pollution with microstructural changes over time. Two hundred four hair samples from 2 Chinese cities with distinct pollution exposure were collected, and chromatographic-mass spectrometry was used to quantify the PAH-exposure profiles of each individual sample. This allowed us to define a group of less contaminated hair samples as well as a more contaminated group. Using transmission electron microscopy (TEM) together with quantitative image analysis and blind scoring of 82 structural parameters, we find that the speed of naturally occurring hair-cortex degradation and cuticle delamination is increased in fibers with increased PAH concentrations. Treating nondamaged hair fibers with ultraviolet (UV) irradiation leads to a more pronounced cortical damage especially around melanosomes of samples with higher PAH concentrations. Our study shows the detrimental effect of physiological concentrations of PAH together with UV irradiation on the hair microstructure but likely can be applied to other human tissues.

Implementation and Integration of Microbial Source Tracking in a River Watershed Monitoring Plan

Fecal pollution of water bodies poses a serious threat for public health and ecosystems. Microbial source tracking (MST) using host specific bacteria are used to track the source of this potential pollution and be able to perform a better management of the pollution at the source. In this study we tested 12 molecular MST markers to track human, ruminant, sheep, horse, pig and gull pollution to determine their usefulness in their application for an effective management of water quality. First, the potential of the selected markers to track the source was evaluated using fresh fecal samples. Subsequently, we evaluated their performance in a catchment with different impacts, considering land use and environmental conditions. All MST markers showed high sensitivity and specificity, although none achieved 100% for both. Although some of the MST markers were detected in hosts other than the intended ones, their abundance in the target group was always several orders of magnitude higher than in the non-target hosts, demonstrating their suitability to distinguish between sources of pollution. The MST analysis matched the land use in the watershed allowing a very accurate assessment of the main hazards and sources of pollution, in this case mainly human and ruminant pollution. Correlating environmental parameters like temperature and rainfall with the levels of the MST markers provided insight into the dynamics of the pollution along the catchment. The levels of the human associated marker showed a significant negative correlation with rainfall in human polluted areas suggesting a dilution of the pollution, whereas at agricultural areas the ruminant marker increased with rainfall. There were no seasonal differences in the levels of human marker, indicating human pollution as a constant pressure throughout the year, whereas the levels of the ruminant marker was influenced by the seasons, being more abundant in summer and autumn. Performing MST analysis integrated with land uses and environmental data can improve the management of fecal polluted areas and set up good practices.

Microbial diversity in freshwater samples and their contaminating human and bovine hosts

DNA extracted from feces (human and bovine) and water samples was used for the massive pyrosequencing of the hypervariable V3 region of the 16S rRNA gene, revealing 4296 operational taxonomic units (OTUs). The greatest diversity was observed in samples of cattle feces, and the smallest diversity was found in a pristine water sample. Firmicutes was the predominant group in samples of human feces, while in bovine feces the dominant groups were Firmicutes and Bacteroidetes. The interaction network showed that the stool samples had the greatest diversity and, among the water samples, the one with human pollution source had the highest diversity. The LEfSe method was used to identify host biomarkers. Actinobacteria, Betaproteobacteria, and Firmicutes were identified as human biomarkers, while for cattle, the potential markers were Bacteroidetes, Tenericutes, and Spirochaetes. Host-specific markers were identified, but were not found in the water samples, suggesting either that the tools used did not have the resolution to identify markers in environmental samples, or that the contamination in the water bodies was mixed. Additionally, as the host-specific markers were isolated from non-autochthonous microorganisms, they could be affected by adverse environmental effects including physical-chemical factors and competition with native organisms.

Microbial diversity in freshwater samples and their contaminating human and bovine hosts

DNA extracted from feces (human and bovine) and water samples was used for the massive pyrosequencing of the hypervariable V3 region of the 16S rRNA gene, revealing 4296 operational taxonomic units (OTUs). The greatest diversity was observed in samples of cattle feces, and the smallest diversity was found in a pristine water sample. Firmicutes was the predominant group in samples of human feces, while in bovine feces the dominant groups were Firmicutes and Bacteroidetes. The interaction network showed that the stool samples had the greatest diversity and, among the water samples, the one with human pollution source had the highest diversity. The LEfSe method was used to identify host biomarkers. Actinobacteria, Betaproteobacteria, and Firmicutes were identified as human biomarkers, while for cattle, the potential markers were Bacteroidetes, Tenericutes, and Spirochaetes. Host-specific markers were identified, but were not found in the water samples, suggesting either that the tools used did not have the resolution to identify markers in environmental samples, or that the contamination in the water bodies was mixed. Additionally, as the host-specific markers were isolated from non-autochthonous microorganisms, they could be affected by adverse environmental effects including physical-chemical factors and competition with native organisms.