Correlation between L. pneumophila sg 2–14 and TPC in the shower system of School 1 over a period of 1 year.

The arrows indicate time points for hot water treatment and the star represents a one-time chlorination treatment (Concentrate of di-n-decyl dimethylammonium chloride (箭头指示热水处理的时间节点，星号代表一次性氯化处理（双癸基二甲基氯化铵浓缩液（Concentrate of di-n-decyl dimethylammonium chloride）（