ABSTRACT
Objective To assess the hygienic status of the central air conditioning ventilation system in public places by fuzzy comprehensive evaluation method.Methods According to the comprehensive evaluation method of public place (WS /T 199—2001),a fuzzy comprehensive evaluation method was applied to evaluate central air conditioning ventilation systems in 15 large public places of Jinhua City.Results The qualified rate of central air ventilation system was 53.30%, and the qualified rates of total number of bacteria,the fungi,β-hemolytic streptococcus in air blow and Legionella bacteria in the cooling water all reached 100.00%.At the same time,the qualified rate of bacteria,fungi and dust volume in internal surface of pipe were 93.33%,86.67% and 80.00% respectively.The qualified rate of PM10 was 86.67%. Among 15 central air conditioning ventilation systems,13 systems were evaluated as level Ⅰ,and the other two was as level Ⅱand Ⅳ respectively.TAAlso,14 evaluated units got the fuzzy comprehensive indexes of central air ventilation less than 0.5.Conclusion The hygiene status of central air conditioning ventilation system in Jinhua is acceptable,and the management of hygiene quality should be strengthened.
ABSTRACT
Objective To study oxidative damage for occupational lead exposure, the relationship between serum lead and oxidative stress enzymes, and the mechanism of lead poisoning. Methods The lead content in the air was determined by flame atomic absorption spectrophotometric method, the lead concentration in serum was determined by graphite furnace atomic absorption spectrophotometric method. Superoxide dismutase (SOD) and malondialdehyde (MDA) as the effect indicators of oxidative stress were used to analyze the relationship between blood lead and the indicators. Results Five workplaces were monitored. The lead concentration in exposed group (244.27±124.59ug/L) was significantly higher than that in control group (P<0.01). The SOD activity in exposure group was 61.27±6.97KU/L not significantly different from that in control group (P>0.05), while MDA concetration in exposure group (9.42±3.89mmol/L) was significantly higher than in control group (P< 0.01). There was positive correlation between serum MDA and blood lead concentration (r = 0.3, P < 0.01) . The effects of smoking and drinking on the SOD activity and MDA content were not statistically significant. Conclusion Occupational lead exposure increases the blood lead level. It is inconsistent between the changes of lead concentration in workplace air and in blood lead. Blood lead is a sensitive indicator as the lead internal exposure. The higher blood lead level is, the higher the SOD activity and the MDA concentration, the more seriousthe oxidative damage is.