Table 1 The concentration of heavy metals (mg kg⁻¹ of dry weight) on edible organs vegetables grown in different world cities

Leaf

Lettuce

Lactuca sativa L.

France

[136]

355.0

France

[206]

122.0

1.7

6.8

29.1

South Korea

[141]

0.70–1.26

0–0.08

6.54–8.36

0.36–0.40

49.6–62.2

Romania

[134]

68.3–118

4.9–6.7

11.8–13.8

121.0–301.0

Benin

[207]

77.1–77.8

0.3

3.8–7.9

56.4–107.8

Ecuador

[208]

0–1.18

0–0.56

White cabbage

Brassica oleracea subsp. capitata (L.) Metzg

Germany

[209]

2.6

0.41

6.6

1.0

0.81

46.5

Benin

[207]

52.6–78.9

0–0.1

1.8–3.9

–

–

44.1–85.4

China

[210]

1.71^a

0.13^a

1.40^a

–

–

5.95^a

Chinese cabbage

Brassica rapa var. pekinensis (Lour.) Hanelt

China

[210]

1.17^a

0.34^a

1.69^a

–

–

12.4^a

Pakchoi

Brassica rapa var. chinensis (L.) Kitam

China

[210]

2.79^a

1.2^a

3.07^a

–

–

14.3^a

Leek

Allium ampeloprasum L.

China

[210]

4.03^a

0.39^a

2.17^a

–

–

8.63^a

Persley

Petroselinum crispum (Mill.) Fuss

France

[206]

298.7

0.8

4.4

–

–

25.4

Spinach

Spinacia oleracea L.

South Korea

[141]

0.59–1.16

0

7.17–50.9

0.11–0.36

91.53–122.1

Fruit

Tomato

Lycopersicon esculentum Mill

Germany

[209]

0.1–6.7

0.01–0.79

3.5–16.0

0.03–0.70

0.11–0.63

15.8–84.7

Ecuador

[208]

0–2.33

0–0.66

China

[210]

0.72^a

0.39^a

1.39^a

3.48^a

Pepper

Capsicum annuum L.

China

[210]

1.94^a

0.23^a

2.0^a

4.3

Green beans

Phaseolus vulgaris L.

Germany

[209]

0.1–3.5

0–0.04

3.5–10.5

0.27–1.3

0.08–0.46

32.4–44.2

Root

Carrot

Daucus carota L.

Germany

[209]

1.3–28.5

5.4–23.2

5.4–23.2

0.07–0.47

0.1–2.39

23.3–122.8

Belgium

[211]

0.9–9.2^a

5.6–10.9^a

Celery

Apium graveolens

var. Rapaceum (Mill.) Poir

Belgium

[211]

1.6–21.0^a

10.9–40.1^a

Radish

Raphanus sativus L.

China

[210]

1.01^a

0.22^a

0.96^a

3.57^a

Stem

Kohlrabi

Brassica oleracea

var. gongylodes L.

Germany

[209]

0.1–3.1

0.03–0.15

3.2–11.6

0–0.91

0.07–0.54

20.6–50.3