Cadmium levels in the urine of male sewage sludge farmers of Hyderabad, India

Cadmium in Human Diseases: It's More than Just a Mere Metal

Cadmium (Cd), poisoning has been reported from all around the World, causing many deaths annually. Cd is a toxic heavy metal, and is widely present in environment. It has been reported that chronic Cd exposure is associated with kidney disease, osteoporosis, cardiovascular diseases and cancer. Smoking causes exposure to significantly higher Cd levels in humans. Tobacco smoke transports Cd into the lungs. Blood then transport it to the rest of the body where it increases effects by potentiating Cd that is already present from Cd-rich food. Other high exposures of Cd can occur with people, who live near hazardous waste sites, or factories that release Cd into the air and people who work in the metal refinery industry. Breathing of Cd can severely damage the lungs and may even cause death. Multiple studies have shown an association between environmental exposure to hazardous chemicals including toxic metals and obesity, diabetes, and metabolic syndrome. At the same time, the existing data on the impact of Cd exposure on obesity and diabetes are contradictory. On the converse, results of epidemiologic studies linking Cd exposure and Osteoporosis, overweight or obesity are far less consistent and even conflicting, also depending on differences in exposure levels. In turn, laboratory studies demonstrated that Cd adversely affects adipose tissue physiopathology through several mechanisms, thus contributing to increased insulin resistance and enhancing diabetes. However, intimate biological mechanisms linking Cd exposure with human diseases are still to be adequately investigated. Therefore, the aim of the present review was to explore the impact of Cd exposure and status on the risk of Cd in human diseases.

Oxidative Stress and Cardiovascular Dysfunction Associated with Cadmium Exposure: Beneficial Effects of Curcumin and Tetrahydrocurcumin

Cadmium (Cd) is a non-essential heavy metal with high toxicity potential. Humans are exposed to Cd present in diet, polluted air, and cigarette smoke. Cd exposure has been associated with increased risk of chronic diseases, including hypertension, atherosclerosis, diabetes, and nephropathy, all of which could be attributable to dysfunctional endothelial and smooth muscle cells. Cd toxicity is correlated with increased reactive oxygen formation and depletion of antioxidants, resulting in an oxidative stress. Chelation of Cd has proved useful in the removal of the Cd burden. However, several chelating agents cause side effects in clinical usage. Recent studies have shown that the antioxidant compounds curcumin and tetrahydrocurcumin can alleviate vascular dysfunction and high blood pressure caused by Cd toxicity. In chronic Cd exposure, these antioxidants protect vascular endothelium by increasing nitric oxide (NO•) bioavailability and improving vascular function. Antioxidant activity against Cd intoxication results directly and/or indirectly through free radical scavenging, metal chelation, enhanced expression of the antioxidant defense system, regulation of inflammatory enzymes, increase in NO• bioavailability, and reduction of gastrointestinal absorption and tissue Cd accumulation. This review summarizes current knowledge of Cd-induced oxidative stress and cardiovascular dysfunction and a possible protective effect conferred by the antioxidants curcumin and tetrahydrocurcumin.

Assessing risk of heavy metals from consuming food grown on sewage irrigated soils and food chain transfer

Heavy metal pollution of soils resulting from sewage and wastewater irrigation is causing major concern due to the potential risk involved. In the present study Musi River and its environs were assessed for heavy metal contamination. The study area was assessed for Zn, Cr, Cu, Ni, Co and Pb in soils, forage grass, milk from cattle, leafy and non-leafy vegetables. Partitioning pattern of soil revealed high levels of Zn, Cr, and Cu associated with labile fractions, making them more mobile and plant available. The associated risk was assessed using hazard quotient (HQ). Human risk was assessed in people known to consume these contaminated foods by analyzing metals concentrations in venous blood and urine. Results showed high amounts of Pb, Zn, Cr, and Ni compared to permissible limits. HQ was found to be high for Zn followed by Cr and Pb with special reference to leafy vegetables particularly spinach and amaranthus.

Health effects of wastewater reuse for agriculture in the suburbs of Asmara city, Eritrea

The health impact of utilization of raw domestic sewage for vegetable cultivation in the suburbs of Asmara, Eritrea, was assessed. Results showed heavy contamination of vegetables by fecal coliforms and Giardia cysts as well as other pathogenic bacteria such as Shigella and Salmonella. Stool samples from 75 occupationally exposed farmers revealed that 45% of them were harboring Giardia cysts. Dietary intake of raw greens (lettuce, cabbage) grown on the raw sewage appears to cause giardiasis, amebiasis, and diarrhea in the farming community as well as in the surrounding area. Comparison of hospital data from the affected area with data from other areas of Eritrea indicated that agriculture use of untreated wastewater was the major cause of the increase in giardiasis and other gastrointestinal diseases.

Prevalence of Giardiasis due to wastewater reuse for agriculture in the suburbs of Asmara City, Eritrea

A study was undertaken to assess the health impact of utilization of the raw domestic sewage for vegetable cultivation in the suburbs of the capital city of Asmara, Eritrea. Standard techniques were adopted for the analysis of the samples. Results showed heavy contamination of vegetables by faecal coliforms as well as with Giardia cysts. Stool samples of 75 farmers who were occupationally exposed revealed that 45% of them were harbouring giardia cysts. The dietary intake of raw salads (lettuce, cabbage) grown on the raw sewage appear to be a causative factor of Giardiasis in the farming community as well as in the town of Tsadachristian located on the suburbs of the capital city of Asmara. The hospital data of the affected town is compared with other towns of Eritrea. The result indicates agriculture reuse of untreated wastewater is a major cause for the increase in Giardasis.