A Study on Heavy Metals Leakage from PVC and Polypropylene Pipes used in Isfahan's Water Distribution System

Various chemicals are used to produce polymers, leakage of polymer materials over the time, can cause health problems The aim of this research was to evaluate the leakage of heavy metals from the PVC and polypropylene pipes used in the water distribution system in Isfahan.

Four brands of PP pipes and two various types of PVC pipes were analyzed in this study.Concentration and leakage of heavy metals (lead, cadmium, nickel, chromium, zinc and tin) at 20 ° C were measured and compared with national standards of Iran, US Environmental Protection Agency (EPA) and the World Health Organization (WHO) guidelines.

Mean lead concentration in used and new PVC pipes was higher than other pipes and there was significant difference between these two PVC pipes and other pipes in lead concentration. Mean leakage of lead was higher in PP pipes produced in A and B manufacturing plants. Lead leakage was lower than Iranian standards, but exceeds than EPA standards and WHO guidelines in PP pipes produced in A and B manufacturing plants. Cadmium leakage from PP pipes produced in C manufacturing plant exceeds all standards and guidelines.

Inappropriate plastic production process increases the possibility of stabilizers and plasticizers releasing. Regarding direct relation between use of polymer pipes and consumer’s health, control of pipes producer by related institutions is proposed in accordance with make changes in stabilizers and preventing application of heavy metal-based pigments to overcome the mentioned problems.