 Cadmium exposure is a risk factor associated with a large number of illnesses including kidney disease , early <unk> , <unk> , and <unk> diseases . Although studies show a significant correlation between cadmium exposure and occurrence of disease in human populations , a necessary molecular mechanism has not been identified . One hypothesis holds that cadmium is an <unk> <unk> and some experimental studies have shown that it can interact with different <unk> signaling pathways . For example , cadmium can bind to the estrogen receptor alpha , and affect signal transduction along the estrogen and <unk> signaling pathways at low doses . 
