Evans J S, Hawkins N C
Department of Environmental Science and Physiology, Harvard University, School of Public Health, Boston, MA 02115.
Am Ind Hyg Assoc J. 1988 Oct;49(10):512-5. doi: 10.1080/15298668891380141.
To assess compliance with industrial hygiene exposure criteria (e.g., TLVs), it may be necessary to perform statistical tests of hypotheses based on relatively small samples. For pollutants with long biological half-lives, the parameter most relevant for determining the risk faced by workers is the long-term arithmetic average concentration of the pollutant. In industrial environments it is common for pollutant concentrations to be approximately lognormal. Unfortunately, when based on small samples from lognormal distributions, the ordinary Student's t-statistic has some undesirable characteristics which are not recognized widely by practicing industrial hygienists. The difficulties in using the ordinary Student's t-statistic to evaluate the average exposure have been demonstrated. The properties of alternative test statistics have been explored. Some general observations on the implications of these findings have been made.
为评估对工业卫生接触标准（如阈限值）的遵守情况，可能有必要基于相对较小的样本进行假设的统计检验。对于生物半衰期长的污染物，确定工人面临风险时最相关的参数是污染物的长期算术平均浓度。在工业环境中，污染物浓度通常近似呈对数正态分布。不幸的是，当基于来自对数正态分布的小样本时，普通的学生t统计量具有一些不良特性，而实际从事工业卫生工作的人员并未广泛认识到这些特性。已证明使用普通学生t统计量评估平均接触水平存在困难。已探索了替代检验统计量的性质。已对这些发现的影响进行了一些一般性观察。
