Bioaccessibility and human health risk assessment of metal(loid)s in soil from an e-waste open burning site in Agbogbloshie, Accra, Ghana.

Environmental pollution and human health issues due to unrestricted electronic waste (e-waste) recycling activities have been reported at a number of locations. Among different e-waste recycling techniques, open burning of e-waste releases diverse metal(loid)s into the environment, which has aroused concern worldwide. In human health risk assessments (HHRAs), oral ingestion of soil can be a major route of exposure to many immobile soil contaminants. In vitro assays are currently being developed and validated to avoid overestimation of pollutants absorbed by the human body when calculating total pollutant concentrations in HHRAs. In this study, Cu, As, Cd, Sb, and Pb bioaccessibility in polluted soils (n = 10) from e-waste open burning sites at Agbogbloshie in Accra, Ghana, was assessed using an in vitro assay, the physiologically based extraction test. A bioaccessibility-corrected HHRA was then conducted to estimate the potential health risks to local inhabitants. The in vitro results (%) varied greatly among the different metal(loid)s (Cu: 1.3-60, As: 1.3-40, Cd: 4.2-67, Sb: 0.7-85, Pb: 4.1-57), and also showed marked variance between the gastric phase and small intestinal phase. The particle sizes of soil samples and chemical forms of metal(loid)s also influenced bioaccessibility values. Using these bioaccessibility values, both the hazard index and carcinogenic risk were calculated. The hazard index was above the threshold value (>1) for 5/10 samples, indicating a potential health risk to local inhabitants.

Analysis of COMT Val158Met polymorphisms and methylation in Chinese male schizophrenia patients with homicidal behavior.

Schizophrenia is a severe mental disorder, and its mechanisms have not been fully elucidated. A functional single nucleotide polymorphism (SNP) present in the catechol-O-methyltransferase (COMT) gene, Val158Met (rs4680) (Chr22: 19,963,498), is possibly related to the violent behavior of schizophrenia patients. However, the specific variant that causes violent behavior is still unknown. Since the Val variation of Val158Met (rs4680) introduces a CG site into the sequence, the methylation level of the Val158Met (rs4680) region may also have an association with the homicidal behavior of schizophrenia patients. A case-control study was conducted that included 100 normal males, 100 schizophrenia inpatients, and 100 schizophrenia inpatients with homicidal behavior. A polymorphism of Val158Met (rs4680) and the methylation levels were analyzed by pyrosequencing. Compared to Met carriers, the Val/Val genotype was significantly associated with the homicidal behavior of schizophrenia patients. In addition, the methylation levels of the Val158Met (rs4680) region were significantly different between the three groups. Moreover, the methylation level of an rs4680-related CpG site was significantly associated with the Val/Val genotype which may contribute to the homicidal behavior of schizophrenia patients. In this study, we showed that the Val allele at Val158Met (rs4680) may be associated with the homicidal behavior of schizophrenia patients as well as that the methylation level of Val158Met (rs4680) could be affected by the variation of Val158Met (rs4680) and eventually contribute to the violent behavior of schizophrenia patients.