Heavy metals and metalloids (HMs) are environmental pollutants, most notably cadmium, lead, arsenic, mercury, and chromium. When HMs accumulate to toxic levels in agricultural soils, these non-biodegradable elements adversely affect crop health and productivity. The toxicity of HMs on crops depends upon factors including crop type, growth condition, and developmental stage; nature of toxicity of the specific elements involved; soil physical and chemical properties; occurrence and bioavailability of HM ions in the soil solution; and soil rhizosphere chemistry. HMs can disrupt the normal structure and function of cellular components and impede various metabolic and developmental processes.
Fertilizers | Cadmium Content (mg Kg−1) | |
---|---|---|
Based on Product | Based on P Content | |
Complete fertilizer | 23–29 | 418–527 |
Single superphosphate | 16–26 | 186–302 |
Superphosphate | 13–34 | 151–395 |
Rock phosphate | 7.2–47 | 54–303 |
High analysis fertilizer | <0.6–5.6 | 15–118 |
Double superphosphate | <0.6–12 | <3.6–72 |
Triple superphosphate | 0.8–7.0 | 24–35 |
Mono-ammonium phosphate | 1.8–8.1 | 12–37 |
Di-ammonium phosphate | 4.3–6.6 | 22–28 |
Elements | MAX | MIN | Fold Difference |
---|---|---|---|
mg Kg−1 Soil | |||
Cd | 0.65 | 0.06 | 10.8 |
Cu | 171.5 | 21.0 | 8.2 |
Ni | 36.9 | 28.7 | 1.3 |
Pb | 38.0 | 20.5 | 1.9 |
Zn | 433 | 71.9 | 6 |
Chemical Name | Formula | HM Elements |
---|---|---|
Insecticides | ||
Aluminum phosphide | AIP | Al |
Lithium perfluorooctane sulfonate | ||
C | ||
8 | ||
F | ||
17 | ||
LiO | ||
3 | S | Li |
Sodium meta-arsenite | NaAsO2 | As |
Fungicide | ||
Copper oxide | CuO | Cu |
Mercuric chloride | ||
HgCl | ||
2 | ||
Hg | ||
Trade Name | Technical Name | Metal Impurities (ppb) * | |||
---|---|---|---|---|---|
Insecticides | Defarge et al. [38] | ||||
Pyrinex® | Chlorpyriphos | As (390), Cr (800), Ni (1200) | |||
Aluminum silicate | Al2Si2O7 | Al | |||
Arsenic acid | H3 | ||||
Polysect® | Acetamiprid | Ni (50) | AsO4 | As | |
Copper bis(3-phenylsalicylate) | |||||
Fungicides | Copper acetoarsenite | C4H6As6Cu4O16 | As, Cu | ||
Defarge et al., | [ | 38 | Copper oxide | Cu2O | Cu |
Copper carbonate | CH2 | ||||
C | |||||
26 | |||||
H | 18CuO6 | Cu | |||
Copper abietate | C40H58CuO4 | Cu | |||
Copper acetate | Cu2(CH3COO)4 | Cu | |||
Copper carbonate | CH2Cu2O | Cu | |||
Copper chloride | |||||
Cacodylic acid | |||||
Folpan® | Folpet | As (260), Cr (2000), Ni (1200) | |||
(CH | |||||
3 | |||||
) | |||||
2 | |||||
AsO(OH) | |||||
As | |||||
] | |||||
Eyetak® | Prochloraz | As (200), Co (90), Cr (200), Ni (190), Pb (12) | Cu2O | Cu | |
Maronee® | Tebuconazole | As (90), Co (50), Cr (100) | Copper naphthenate | C22H14CuO4 | Cu |
Opus® | Epoxiconazole | Cr (90), Ni (60) | Lead arsenate | AsHO4Pb | As, Pb |
Pictor® | Boscalid | As (300), Co (275), Cr (1000), Ni (600) | CuCl | ||
Teldor® | Fenhexamid | As (575), Cr (800), Ni (800) | 2 | ||
Herbicides | Cu | ||||
Defarge et al. | [ | 38] | |||
R 3+® | Glyphosate-based formulations | As (375), Co (50), Cr (175), Ni (20) | |||
R Bioforce® | As (260), Cr (200), Ni (120) | ||||
R Express® | As (60) | Copper hydroxide | |||
R GT+® | As (450), Co (150), Cr (100), Ni (50), Pb (10) | H2O2Cu | Cu | ||
Copper naphthenate | C22H14CuO4 | Cu | |||
Copper oxychloride | (ClCu2H3O3)2 | Cu | |||
Copper sulphate | CuSO4-Ca(OH)2 | Cu | |||
Mercuric oxide | HgO | Hg | |||
Mercurous chloride | Hg2Cl2 | Hg | |||
Methoxyethylmercury chloride | C3H7ClHgO | Hg | |||
As (75), Cr (250), Ni (100), Pb (100) | Methoxyethylmercury acetate | C5H10HgO3 | Hg | ||
Insecticides | Alnuwaiser [39] | Phenyl mercuric acetate | C8H | ||
Sniper® | 8O2Hg | Hg | |||
Fipronil | Zn (506), Cu (423), Cr (746), Co (275), Pb (88) | Phenylmercury chloride | C6H5ClHg | Hg | |
CyperCel® | Cypermethrin | Zn (2389), Cu (669), Cr (373), Co (18), Pb (807) | Phenylmercury nitrate | C | Rodenticides |
R WeatherMax® | As (500), Cr (100), Ni (20), Pb (10) | ||||
Bayer GC® | As (75), Co (60), Cr, (110) Ni (20) | 6H5HgNO3 | Hg | ||
CyperSafe® | Cypermethrin | Zn (968), Cu (464), Cr (10), Co (6), Pb (119) | Sodium arsenite | NaAsO2 | As |
Scope 60® | Asaybrmthrin | Zn (527), Cu (539), Cr (437), Co (23), Pb (39) | Zinc borate | ZnB3O | |
Brodor® | 4(OH)3 | PermethrinZn, B | |||
Zn (10), Cr (16), Pb (186) | |||||
Clinic EV® | As (400), Co (90), Cr (150), Ni (20) | ||||
ClashBarium carbonate | BaCO | ||||
Glyfos® | Zinc oxide | ®ZnO | Acephate + Buprofezin | Zn (1078), Cr (73), Co (39), Pb (1316) | |
3 | Ba | ||||
As (200), Cr (1100), Ni (50), Pb (30) | Zn | ||||
Acefed® | Mithomail | Cu (19), Cr (48), Co (4), Pb (121) | |||
Lanid® | - | Cu (128), Cr (60), Pb (98) | |||
Probalt® | - | Cu (179), Cr (85), Co (25), Pb (46) | |||
Nourcam® | - | - | |||
Madar® | - | Zn (10), Cu (66), Cr (16), Co (10), | |||
PifPaf® | - | Cu (110), Co (5), Thallium, Tl (19), Pb (12) | |||
Paygon® | - | Zn (52), Tl (15), Pb (19) |
Source | Level | Zn | Cu | Pb | Cd | Cr | Hg | As | Ni |
---|---|---|---|---|---|---|---|---|---|
0.2 | |||||||||
0.6 | |||||||||
1.2 | |||||||||
FD | |||||||||
10 | |||||||||
26 | |||||||||
12 | |||||||||
4.7 | |||||||||
2.8 | 12 | 4.3 | 10 |
Elements | Maximum Permissible Level (mg Kg−1) | Cumulative Loading Rate (Kg ha−1) | Monthly Average Concentrations (mg Kg−1) | Annual Loading Rate (Kg ha−1) | ||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Pig | MAX | 4639 | 1288 | 23 | 60 | |||||||||||||
As | 75 | 85 | (21.3) | 0.3 | 41 | 89 | 19 | |||||||||||
41 | 2.0 | |||||||||||||||||
4.62 | (23.1) | 15.20 (7.6) |
0.52 (5.2) |
0.02 (2.0) |
1.15 (0.2) |
- | Ahmed et al. [16] | MIN | 100 | 73 | 0.3 | 0.04 | 3.5 | Cd | 85 | 39 | 39 | |
Max level (FD) |
0.94 (9.4) | 0.0 | 0.01 | 4.7 | ||||||||||||||
0.61 | 1.9 | |||||||||||||||||
(3.1) | 0.86 | (0.4) | - | 0.04 (4.0) |
0.19 (0.04) |
0.12 (0.6) |
Berihun et al. [58] | FD | 46 | 18 | 77 | 1500 | 24 | - | 8900 | 4.0 | ||
Cr | 3000 | 3000 | 1200 | 150 | Chicken | MAX | 578 | 314 | 33 | 4.1 | 251 | 0.5 | 23 | 39 | ||||
Cu | 4300 | 1500 | 1500 | 75 | MIN | 166 | 18 | 3.0 | 0.03 | 4.0 | 0.02 | 0.05 | 5.2 | |||||
Pb | 840 | 300 | 300 | 15 | FD | 3.5 | 17 | 11 | 137 | 63 | 25 | 460 | 7.5 | |||||
Hg | 57 | 17 | 17 | 0.9 | Duck | MAX | 682 | 199 | 41 | 2.5 | 64 | 0.07 | 6.8 | 16 | ||||
Ni | 420 | 420 | 420 | 21 | MIN | 98 | 35 | 4.5 | 0.3 | 7.0 | 0.03 | 0.01 | 8.4 | |||||
Se | 100 | 100 | 36 | 5.0 | FD | 7.0 | 5.7 | 9.1 | 8.3 | 9.1 | 2.3 | 680 | 1.9 | |||||
Zn | 7500 | 2800 | Poultry | MAX | 682 | 314 | 41 | 4.1 | 251 | 0.5 | 23 | 39 | ||||||
MIN | 77 | 15 | 2.0 | 0.03 | 2.5 | 0.02 | 0.01 | 5.2 | ||||||||||
2800 | 140 | FD | 8.9 | 21 | 21 | 137 | 100 | 25 | 2300 | 7.5 | ||||||||
Zineb | ||||||||||||||||||
C | ||||||||||||||||||
4 | ||||||||||||||||||
H | ||||||||||||||||||
6 | ||||||||||||||||||
N | ||||||||||||||||||
2 | ||||||||||||||||||
S | ||||||||||||||||||
4 | ||||||||||||||||||
Zn | ||||||||||||||||||
Zn | ||||||||||||||||||
Herbicides | ||||||||||||||||||
Arsenic acid | H3AsO4 | As | ||||||||||||||||
Calcium arsenate | As2Ca3O8 | As | ||||||||||||||||
Zinc phosphide | ||||||||||||||||||
Zn | ||||||||||||||||||
3 | P2 | Zn | ||||||||||||||||
Thallium sulfate | Tl2SO4 | |||||||||||||||||
Glyphogan® | As (320), Co (125), Cr (100), Ni (40) | |||||||||||||||||
Pavaprop-G® | Cr (110), N (190) | |||||||||||||||||
Radical Tech+® | As (270), Co (70), Cr (50), Ni (50) | |||||||||||||||||
Lonpar® | 2,4-D | As (160), Cr (150), Ni (180) | ||||||||||||||||
Matin® | Isoproturon | As (100), Cr (100), Ni (30), Pb (25) | ||||||||||||||||
Elements | Cr | Cu | Zn | As | Cd | Pb | Ni | References | |
---|---|---|---|---|---|---|---|---|---|
mg L−1 | |||||||||
Max level (FD) * |
2.13 | ||||||||
FAO limit | |||||||||
0.10 | 0.20 | 2.00 | 0.10 | 0.01 | 5.00 | 0.20 | |||
Cattle | |||||||||
MAX | |||||||||
816 | |||||||||
174 | |||||||||
32 | 3.4 | 79 | 0.6 | 6.3 | 19 | ||||
MIN | 49 | 12 | 1.6 | 0.04 | 0.8 | 0.02 | 0.01 | 4.2 | |
FD | 17 | 15 | 20 | 85 | 99 | 30 | 630 | 4.5 | |
Sheep | MAX | 431 | 215 | 20 | 1.4 | 22 | 2.4 | 2.6 | 12 |
MIN | 42 | 8.4 | 1.7 | 0.3 | |||||
Starane | |||||||||
® | |||||||||
Fluoroxypyr | |||||||||
Sodium arsenite | |||||||||
NaAsO | |||||||||
2 | |||||||||
As | |||||||||
8.0 | |||||||||
Tl | |||||||||
Defoliants | |||||||||
Sodium dichromate | |||||||||
Na | 2Cr2O7 | Cr | |||||||
Zinc chloride | ZnCl2 | Zn |