RESUMO
Weighing collected samPles to determine the IPS' content of indoor air and adopting the length of collecting time as 4 , 6and8 hours, the experimental accuracy and analytic errors were seParatdy analysed in different length of collecting time, as a result, when the IPS' content is less than 0.300mg.m-3, the smallest co-fficient of variation came from the statistic result of which its length of collecting time was 8 hours and in anaylsis its Permissible relative errors were not more than 10%, so it could be determined that the apporiate length of ccollecting time was 8 hours ( CIP
RESUMO
Objective In order to understand the quality of drinking water sources and the environment of the Qinghai-Tibet Railway areas. Methods In 2002-2004, the first and second phase of the project of Qinghai-Tibet Railway, 37 sampling sites were chosen in the dry and rainy seasons and the water samples were analyzed according to the national standard test methods. Results In the first phase of the project, the eligible rates of the 39 test indexes of the water sources of 23 sampling sites in the Qinghai-Tibet Railway areas were 82%-95% in the dry season and some decreased in the rainy season. In the second phase, the eligible rates of the test indexes of the water sources of 14 sampling sites were 50%-100% in dry season and in the rainy season, the trend was the same as in the first phase. Conclusion Among the 37 water resources in the Qinghai-Tibet railway areas,the percent of gradeⅠ, gradeⅡ, grade Ⅲ and above grade Ⅲ water source was 67.57%,13.51%,2.70% and 16.22% respectively, some water sources can not be used as the drinking water sources due to the bad quality.