| Nowadays, with the swimming became gradually popular, the water quality and safety in swimming poll have attracted more and more people’s attention. In order to avoid the polluted water in swimming pool causing infectious diseases and endangering the health of swimmers, we use chlorine preparations for disinfecting swimming pool water regularly to ensure the health of swimmers. However, chlorine can disinfect the pool water, it would also react the natural organic matters and a variety of organic matters which is bring by human, such as chemical skin care products and body metabolites, this reaction can product disinfection byproducts, such as chloroform. Chloroform is the main disinfection byproducts in swimming pool, it can be harmful to human’s liver, kidney and procreation. And this substance has high volatility, so not only in the water but also in the air are full of this toxic organic matter.At present, the researches of influence factors of chloroform concentration change in swimming pool were focus on chemical dosing, reaction time and concentration of precursor. Although the toxicity of chloroform on human body has draw corresponding attention, the high cost of testing, monitoring difficulties in the indoor swimming pool, most countries, including China, the United States and Britain will not be included in the routine monitoring of chloroform monitoring project, so whether or not we can find a biological indicator to indicate water and air chloroform concentrations in indoor swimming pool becomes necessary. It can be seen from above, this study analyzed the relationship between p H, temperature, agitation rate in swimming pool water and the concentration of chloroform. Chose Daphnia pulex and earthworms as test organisms, and exposed them int o the chloroform environment that was generated by disinfection, then observed the toxic effects and behavior of the test organisms to chloroform, and explore the possibility of the two organisms used as indicators to indicate the indoor swimming pool wate r and the concentration of chloroform in the air is exceeded. To better understand the impact of factors in the indoor pool, the toxicity of indoor swimming pool water and air lower concentrations of chloroform, explore the indicator organisms which can indicate whether the excessive concentration of chloroform, for better monitoring the water and air content of chloroform in indoor swimming pool. what’s more, try to explore some measures to reduce chloroform which was generated in swimming pool and increase the swimmers’ health risks. This subject adopts the single factor experiment, and the toxicity test of reaction between typical precursor substance and common chloride reagent which generate chloroform for daphnia pulex and earthworm, the effect factors of swimming pool chloroform formation--p H, temperature and stirring rate, and acute toxicity test of chloroform to daphnia pulex, chloroform gas avoidance behavior and subacute toxicity test of earthworms was studied, and obtain the following main research results:(1) The chloroform concentrations in swimming pool is proportional with p H while the chloroform and agitation rate become negative correlation. The chloroform concentrations in swimming pool also increased with the temperature increased, after the water temperature is greater than 25 ℃, high temperature caused chloroform evaporated, which make the chloroform concentrations in water had a reduced tendency.(2) Daphnia pulex were exposed to tryptophan chlorination process to produce chloroform environment during 24 hours, the LC50 of chlorine dosing to daphnia pulex was 38.496μg/L(95% confidence interval was between29.472 μg/L ~ 49.361 μg/L). LC100 was 147.78 μg/L(95% confidence interval was between96.191μg/L ~ 388.165μg/L).(3) Daphnia pulex can be used as indicator organisms of chloroform concentration in swimming pool water, assuming that the pool establish a biological indicator small pool lonely, when daphnis’ mortality reached 50% in the biological indicator small pool, the chloroform concentrations in the swimming pool water will exceed the FINA standard(20μg/L) at that time.(4) Earthworm can be used as an indicator organism of air chloroform concentrations in indoor swimming pool, when the earthworm which stay in biological indicator area of indoor swimming pool show complete avoidance behavior, the air chloroform concentration in indoor swimming pool will be equal or greater than 2998.322μg/m3 at that time, which may threat to the health of swimmers and staff.(5) During fifteenth days of testing, earthworms’ physiological feature such as weight and body surface color change, body fluid effusion can be used for indicating the air chloroform in swimming pool. |
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