Table 1.

National diagnostic criteria for the occupational chronic lead poisoning in China.

Grades	Diagnostic Criteria
Observed object	Have a close history of lead exposure, no clinical manifestations of lead poisoning, have one of the following performance:
	(1)Urinary lead ≥ 70 μg/L or 100 μg/24 h
	(2)Blood lead ≥ 40 μg/dL
Mild poisoning	Blood lead ≥ 60 μg/dL or urine lead ≥ 120 μg/L, and having one of the following performances:
	(1)Urinary δ-aminolevulinic acid (ALA) ≥ 8 mg/L
	(2)Blood free erythrocyte protoporphyrin (FEP) ≥ 200 μg/dL
	(3)Erythrocyte zinc protoporphyrin (ZPP) ≥ 2.91 μmol/L
	(4)Abdominal pain, bloating, constipation and other symptoms
Moderate poisoning	On the basis of mild poisoning, with one of the following symptoms:
	(1)Abdominal cramps
	(2)Anemia
	(3)Mild peripheral neuropathy
Severe poisoning	With one of the following manifestations:
	(1)Lead paralysis
	(2)Toxic encephalopathy