Epidemiological study is statistical analysis of population data (in this case, analyzing fo ra co rrelation between the amount of Thimerosal received with the incidence of neurological diso rders).

• 免疫学研究是人口数据的统计分析（在这种情况下，也就是分析硫柳汞的数量与神经系统疾病发病率的关联）。