*3.3.2 Effects of lead on human health*

Drinking water is one of the major sources of human exposure to lead [115]. Lead particularly targets the nervous system, blood, and kidney [116]. Many studies found associations between low level environmental Pb exposure and chronic kidney disease, a general term for heterogeneous disorders affecting the structure and function of the kidney (CKD) [117, 118]. Long-term lead exposure may generate irreversible functional and morphological renal changes [119], distal motor neuropathy and possibly seizures and coma [120]. Infants and small children are more sensitive to the effects of lead, which moreover is transported through the placenta to the foetus [121]. Lead accumulation in fetuses and small children might cause developmental disruption in terms of neurological impairment characterized by a decrease of cognitive faculties, which can be reversible or not, evaluated by psychomotor tests such as the verbal IQ (Intellectual Quotient) test [27, 109]. The period when IQ is most affected is from birth to about 4 years of age [122].

Scientific literature on lead water pollution reports "Lead remains a problem in drinking water in many parts of the world, with millions of properties served by distribution systems containing lead components. Strong links have been established between human exposure to lead and health effects in both adults and children. As a result, the allowable levels of lead indrinking water have generally become lower. Implementation of these regulations is difficult with the controls available. Future recommendations for aspiring to zero lead in drinking water are: (i) improving sampling, monitoring and modeling; (ii) Wider application of shortterm pointof- use devices; (iii) replacement of all lead pipes and plumbing through applicable regulations and increased awareness public" [123–126].

*Chemical Pollution of Drinking Water in Haiti: An Important Threat to Public Health DOI: http://dx.doi.org/10.5772/intechopen.97766*

#### *3.3.3 Effects of nickel on human health*

Nickel is insoluble in water. However, when it is in the form of exceptionally fine particles, it ionizes as Ni (II) in water and in body fluids such as blood. During oral exposure, the major effects observed are the death of a child after ingestion of 570 mg of nickel/kg [127] and intestinal disorders such as nausea, abdominal cramps, and diarrhea [128]. Immunological, hematological, hepatic, renal, genotoxic effects on embryonic development and reproduction have been reported depending on the route of entry into the body [129].
