Comparative study of residual chlorine, temperature and pH effect on swimming pools contamination by some pathogenic bacteria: Study of a case in Algeria.

Despite the various methods used to disinfect swimming pool water, contamination by human health pathogens remains a serious problem. This study aims to compare the physicochemical parameters (residual chlorine level, temperature, and pH) during swimming with the significant contamination of swimming pool water in Blida city, Algeria, by five pathogenic bacteria harmful to human health: Escherichia coli, Enterococcus faecalis, Staphylococcus aureus, Pseudomonas aeruginosa, and Salmonella species. The comparison of pathogenic bacteria averages (colony-forming units (CFU)/100 mL) in the analyzed pool waters with residual chlorine levels (0- < 1 mg/mL) showed that E. faecalis, P. aeruginosa, and S. aureus had significant differences (p ≤ 0.05). Similarly, E. faecalis and P. aeruginosa showed significant differences with pH levels (6.9-7.9), and only P. aeruginosa showed significant differences with temperature (24-29 °C). This study precisely highlights the relationship between residual chlorine, temperature, pH variations, and contamination by the five pathogenic bacteria despite proper water treatment before swimming.