Descriptive statistics of eight metal(loid)s (mg kg⁻¹ wet weight) in fish muscle samples (n = 155)^a.

Heavy metals	Min.	Max.	Mean	Standard deviation	Median	Detection rate (%)	Maximum levels (MLs) for heavy metals in fish				Over-limit ratiob (%)
							Quality standard in China	Commission regulation (EC)	FAO	DHO
Cr	NDc	0.49	0.018	0.048	0.019	33.55	2.00d				0
Ni	ND	0.78	0.019	0.069	0.039	19.35
Cu	0.067	0.97	0.27	0.13	0.25	100.00	50e		30		0
Zn	2.49	51.38	7.97	6.05	5.94	100.00			30
As	ND	0.39	0.052	0.054	0.039	97.42	0.10d			3.00	10.97
Cd	ND	0.009	0.0012	0.0013	0.0010	48.39	0.10d	0.05	0.05	1.00	0
Pb	ND	0.70	0.034	0.074	0.024	70.97	0.50d	0.30	0.20	0.50	0.65
Hg	ND	0.82	0.079	0.14	0.057	74.19	0.50/1.00d	0.50	0.50/1.00f	0.50/1.00f	0.65

^a n means the number of muscle samples.

^bAccording to the quality standard in China.

^cND: Not detected, means the value is lower than the limit of detection. Concentrations less than the LOD were set to ½ LOD for statistical analysis.

^dGB 2762-2017 National Food Safety Standard Maximum Levels of Pollutants in Foods (in Chinese).³⁴ The maximum level for predatory fish is 1.00 mg kg⁻¹, but for all other fish it is 0.50 mg kg⁻¹.

^eNY 5073-2006 Limited Quantity of Poisonous and Harmful Contents of the National Pollution-Free Aquatic Products (in Chinese).³⁵

^fThe maximum level for predatory fish including swordfish is 1.00 mg kg⁻¹ but for all other fish and processed fish, it is 0.50 mg kg⁻¹.