Objective To know the air supply quality of central air-conditioning ventilation system in building before and after cleaning.Methods Three sets of central air-conditioning ventilation systems were selected from a building randomly and 3 air supply ways were selected in each system for the determination of inhalable particulate matter(PM10) and microorganisms in air before and after cleaning.Results After cleaning,the unqualified rate of air quality increased from 11.1%(before cleaning) to 77.8%.The mean value of PM10 increased from 0.051 mg/m3(before cleaning) to 0.083 mg/m3,the median of total account of bacteria and fungus increased from 150 cfu/m3 and 13 cfu/m2(before cleaning) to 570 cfu/m3 and 110 cfu/m3 respectively.Conclusion The air supply quality of central air-conditioning ventilation system in building may be damaged by cleaning if the operation is not in the right way.

Objective To explore the effects of two air sampling methods including natural precipitation method and impacting method for detecting the bacterial count of indoor air of workplace of cosmetic plants. Methods The diameters of 44 glass bacteria-culture plates for those two sampling methods were measured. The indoor air of workplace of cosmetic plants were sampled by those two sampling methods simultaneously. The natural precipitation method was performed for 5- minute exposure ,the impacting method was performed by MAS-100 airborned bacteria sampler at flow rate of 100 L/min for 30 s,2 min,8 min respectively.All of the data on the bacterial counts of air obtained from various sampling ways were statistically analyzed.The measures for quality control of air sampling progress were put forward also. Results The diameters of 44 glass bacteria-culture plates were 8.39-8.70 cm,which were lower than the standard(9 cm?雪. The bacterial counts of air samples collected by natural precipitation method at the same location showed higher coefficient of variation,higher median,lower qualified rate compared with those by impacting method. The bacterial counts of air decreased,when the impacting sampling method was performed for 8 min continuously with sampling volume of 800 L. Conclusion The impacting method with advantages including mere influence from external environment and better precision could be primarily applied for air sampling in general condition,but it might show lower efficiency of collecting the airborne bacteria during the longer sampling period with higher sampling volume. The natural precipitation method with poor precision was suitable for longer term (8-30 min)air sampling in the relatively static environment with lower air flow and highly cleaned air. The bacterial counts of air obtained from natural precipitation method should be corrected if the diameters of glass bacteria-culture plates weren't meet the requirement of the national standard (9 cm?雪.

Objective To explore the concentrations and diameters of the particulates in indoor air of the cosmetic workshops, and provide scientific basis for the testing and evaluation of air cleanliness of the cosmetic workshops. Methods The testing and evaluation on concentrations of the particulates with the diameters of 0.3,0.5,1.0,2.0,3.0,5.0 ?m in indoor air of the cosmetic workshops was carried out among 11 cosmetic manufactures with air filtering and purifying system(air-purified factory) and 13 cosmetic manufactures without air filtering and purifying system but with mechanical ventilation (air-unpurified factory). Results The medians of 0.3～5.0 ?m particulates in air of cosmetic workshops in air-purified factories were significantly lower than those in air-unpurified factories respectively. The concentrations of the particulates in air of cosmetic workshops in air-unpurified factories showed no significant differences compared with those in ambient air.The concentrations of 0.5 and 1.0 ?m particulates showed the significant correlation with those of 0.3?2.0?3.0?5.0 ?m particulates. The concentrations of 2.0?3.0?5.0 ?m particulates showed the significant correlation between each other except for 0.3 ?m particulates. Conclusion The particulates show lower concentration, the air cleanliness doesn't meet the requirement the national standard of 100 000 class in air of cosmetic workshops in air-purified factories. The concentration of 0.5 ?m particulate is suitable for evaluation on air cleanliness in air of cosmetic workshops.

Objective To understand the distribution character of bacteria in the air of cosmetic workshops and present scientific data for the GMP establishment of cosmetic factories.Methods Of cosmetic factories 11 equipped with air depuration systems (ADS)(type I),13 with no ADS(type II)and 9 producing powder products (such as kermes,face mask,etc.) with no ADS(tyoe III)were chosen,distribution character of bacteria in the air was studied there.The bacteria samplings were conducted before and after operation and in winter and spring,summer and autumn respectively.Results The bacterial count in the three kinds of factories was:type I

Objective To investigate the sanitary condition in the inside and outside of a metro station in Guangzhou, and to find the environmental risk factors which can affect the health of staffs of the metro station. Methods To monitor the level of TVOC, inhalable particles, carbon monoxide, benzene, carbon dioxide, formaldehyde and total bacterial count in the air of public places metro hall, metro platform,facilities rooms, tunnel gates, new flow entrances and entrances of subway station respectively in the afternoon and evening, Feb 15, 2006. Results The rate of exceeding standard limit of the pollutants in metro station in the evening was higher than that in the afternoon, and the main items exceeded the limit were inhalable particles, benzene and carbon monoxide, especially in the evening. The level of inhalable particles in the metro hall and facilities rooms both exceeded standard limit. The level of every pollutant in the inside and outside of the station in the evening was higher than that in the afternoon P

Objective To study the contents of antibiotics and antiseptics in the cosmetics sold in markets. Methods The cosmetics sold in professional market and current market (in which cosmetics were retailed) were selected respectively in Guangzhou and the contents of four antibiotics (oxytetracycline, tetracycline, chlortetracycline and chloramphenicol) and five antiseptics (para-hydroxybenzcic acid, methyl para-hydroxybenzoate, ethyl para-hydroxybenzoate, propyl para-hydroxybenzoate and butyl para-hydroxybenzoate) were determined by high performance liquid chromatogram. Results In 111 cosmetics, 30 cosmetics were detected containing oxytetracycline, 62 cosmetics containing tetracycline, 7 cosmetics containing chlortetracycline and 1 cosmetic containing chloramphenicol. The detection rate was 78.4% and the detection rate of antibiotics among various kinds of cosmetics had no significant difference. The antiseptics used in cosmetics were mostly para-hydroxyl compound ester and there were four cosmetics detected containing antiseptics. Conclusion Abusing antibiotics in cosmetics market is very serious. The test standards and methods for antibiotics and antiseptics in the cosmetics should be developed as soon as possible. Cosmetic enterprises need to decrease microbe pollution in the process of production and prohibit adding antibiotics in cosmetics.

Objective: To investigate the association of poor vision with time spent in outdoor activity among students from primary and middle schools, as well as from universities in Guangzhou, so as to provide targeted scientific basis for prevention and control of low vision. Methods: According to the requirements of National Monitoring of Common Diseases and Health Risk Factors among Students Manual, a total of 2 908 students were selected in 1 urban area and 1 suburban county for monitoring and investigation in Guangzhou. Results: The poor vision rate was 69.2% among students in Guangzhou, with girls (74.4%) > boys (64.2%), suburban country (76.3%) > urban areas (54.1%), university (95.0%) > vocational high school (82.5%) > regular high school (81.1%) > junior high school (73.4%) > primary school (45.6%). With the exception of primary students, the severe poor vision has the largest proportion in each age group. The proportion of spending less than 1 or 2 h for outdoor activities per day: girls>boys, suburban country > urban area, university and regular high school are higher. The poor vision rate of students who spent <2 h(72.3%) for outdoor activities daily was higher than those spent ≥2 h(65.6%). Compared with students who spent ≥2 h/d for outdoor activities, those spent < 2 h/d were at 1.24 times risk of being low vision(OR=1.24, 95%CI=1.04-1.48), controlling for the available confounders. Conclusion Poor vision rate of students in Guangzhou is high, occurring mainly with severe impairment and in younger age, the daily outdoor activity time is low. Girls, students from suburban country and junior high school should be considered as the emphasis for prevention and control of low vision.