Lead,mercury, cadmium,chromium, nickel,copper, zinc,calcium, iron,manganese and chromium (VI) levels in Nigeria and United States of America cement dust

This study was aimed at investigating the relative abundance of heavy metals in cement dust from different cement dust factories in order to predict their possible roles in the severity of cement dust toxicity. The concentrations of total mercury (Hg), copper (Cu), chromium (Cr), cadmium (Cd), nickel (Ni), manganese (Mn), lead (Pb), iron (Fe) and chromium (VI) (Cr (VI)) levels in cement dust and clinker samples from Nigeria and cement dust sample from the United States of America (USA) were determined using graphite furnace atomic absorption (GFAAS), while Zn and Ca were measured by flame atomic absorption spectrophotometry (FAAS), and Cr (VI) by colorimetric method. Total Cu, Ni and Mn were significantly higher in cement dust sample from USA (p < 0.05), also, both total Cr and Cr (VI) were 5.4–26 folds higher in USA cement dust compared with Nigeria cement dust or clinker (p < 0.001). Total Cd was higher in both Nigeria cement dust and clinker (p < 0.05 and p < 0.001), respectively. Mercury was more in both Nigeria cement dust and clinker (p < 0.05), while Pb was only significantly higher in clinker from Nigeria (p < 0.001). These results show that cement dust contain mixture of metals that are known human carcinogens and also have been implicated in other debilitating health conditions. Additionally, it revealed that metal content concentrations are factory dependent. This study appears to indicate the need for additional human studies relating the toxicity of these metals and their health impacts on cement factory workers.     

Kolaviron suppresses dysfunctional reproductive axis associated with multi-walled carbon nanotubes exposure in male rats

Reproductive toxicity associated with excessive exposure to multi-walled carbon nanotubes (MWCNTs), which are commonly used in medicine as valuable drug delivery systems, is well documented. Kolaviron, a bioflavonoid isolated from Garcinia kola seeds, elicits numerous health beneficial effects related to its anti-inflammatory, anti-genotoxic activities, anti-apoptotic, and antioxidant properties. However, information on the role of kolaviron in MWCNTs-induced reproductive toxicity is not available in the literature. Herein, we assessed the protective effects of kolaviron on MWCNTs-induced dysfunctional reproductive axis in rats following exposure to MWCNTs (1 mg/kg) and concurrent treatment with kolaviron (50 or 100 mg/kg body weight) for 15 successive days. Results showed that MWCNTs-induced dysfunctional reproductive axis as evidenced by deficits in pituitary and testicular hormones, marker enzymes of testicular function, and sperm functional characteristics were abrogated in rats co-administered with kolaviron. Moreover, co-administration of kolaviron-abated MWCNTs-induced inhibition of antioxidant enzyme activities increases in oxidative stress and inflammatory indices. This is evidenced by diminished levels of tumor necrosis factor-alpha, nitric oxide, lipid peroxidation, reactive oxygen, and nitrogen species as well as reduced activity of myeloperoxidase in testes, epididymis, and hypothalamus of the rats. Biochemical data on the chemoprotection of MWCNTs-induced reproductive toxicity were corroborated by histological findings. Taken together, kolaviron suppressed dysfunctional reproductive axis associated with MWCNTs exposure via abrogation of oxidative stress and inflammation in male rats.