Arsenic (As) is a worldwide public health problem since/because many people in different parts of the world are exposed to this metalloid through drinking water. Among toxic effects produced by As exposure are different types of cancer, such as bladder cancer, which has a high prevalence. As suffers a biotransformation process where methylated species are generated (that are now known to be much more toxic than As), such arsenical species are excreted through urine, thus having contact with bladder. Reason why, it is important determine arsenical species (iAs, MMA and DMA) into flaked bladder cells and thus be able to relate As exposure with cancer development due to accumulation of these species. It is important to note that there are no studies conducted on individuals exposed to As through drinking water and the present investigation is a study where samples were obtained from individuals living in Zimapán, Hidalgo region, where people are environmentally exposed to As via drinking water. It is important to be aware that As exposure causes damage to health and it is necessary to carry out studies that support these findings which will help to take preventive measures.