Group 1 - The investigation revealed significant discrepancies in blood lead level testing data at Tian Shui Second People's Hospital, with multiple children showing abnormal results, some of which were later altered without proper justification [1] - A total of 7 children from the Heishi Peixin Kindergarten were tested, with lead levels ranging from 153.39μg/L to 440.14μg/L, indicating a serious public health concern [1] - The investigation criticized the hospital's management and quality control practices, highlighting a lack of systematic training for laboratory personnel and violations of multiple medical regulations [1] Group 2 - The Gansu Provincial Center for Disease Control and Prevention conducted blood lead testing for 267 samples from Heishi Peixin Kindergarten, but the testing process was flawed due to improper sample handling, leading to inaccurate results [3] - The investigation found that the testing personnel failed to follow proper protocols, such as allowing samples to sit too long before testing, which caused separation of blood components [3] - There were significant deficiencies in the quality control measures and operational standards at the Gansu Provincial CDC, indicating a lack of attention to critical public health tasks [3]