Heavy metals in suspended matter in fresh surface water in the Netherlands, 1988-2000
| Substance/ standards1) | Average annual 90-percentile concentrations | ||||||
| 1988 | 1990 | 1995 | 1998 | 1999 | 2000 | ||
| mg/kg dry matter | |||||||
| Cadmium | Rhine | 9.2 | 6.2 | 4.3 | 3.5 | 3.0 | 7.5 |
| MAC: 18 | Maas | 649 | 62 | 41 | 12 | 12 | 19 |
| DQS: 1.2 | Scheldt | 20.4 | 14.1 | 11.0 | 7.4 | 7.8 | 8.1 |
| IJsselmeer | 2.2 | 3.8 | 2.8 | 1.2 | 1.5 | 1.9 | |
| nationally managed waters | 138.5 | 18.3 | 12.9 | 5.7 | 5.6 | 8.4 | |
| Chromium | Rhine | 134 | 156 | 118 | 114 | 99 | 115 |
| MAC: 570 | Maas | 183 | 257 | 147 | 111 | 129 | 132 |
| DQS: 150 | Scheldt | 194 | 205 | 202 | 135 | 135 | 138 |
| IJsselmeer | 63 | 150 | 96 | 53 | 60 | 62 | |
| nationally managed waters | 148 | 184 | 138 | 102 | 104 | 110 | |
| Copper | Rhine | 151 | 150 | 113 | 125 | 97 | 93 |
| MAC: 110 | Maas | 303 | 315 | 180 | 192 | 233 | 177 |
| DQS: 54 | Scheldt | 164 | 173 | 139 | 105 | 109 | 90 |
| IJsselmeer | 34 | 75 | 62 | 33 | 38 | 32 | |
| nationally managed waters | 154 | 170 | 118 | 110 | 112 | 95 | |
| Mercury | Rhine | 1.7 | 2.1 | 1.3 | 1.3 | 1.0 | 1.1 |
| MAC: 15 | Maas | 2.8 | 3.2 | 2.4 | 1.1 | 1.1 | 1.1 |
| DQS: 0.45 | Scheldt | 1.5 | 1.4 | 1.7 | 1.3 | 1.2 | 1.0 |
| (inorganic | IJsselmeer | 0.6 | 0.9 | 1.1 | 0.5 | 0.4 | 0.4 |
| mercury) | nationally managed waters | 1.7 | 1.8 | 1.6 | 1.1 | 1.0 | 1.0 |
| Nickel | Rhine | 61 | 81 | 62 | 56 | 51 | 60 |
| MAC: 66 | Maas | 69 | 103 | 88 | 68 | 73 | 85 |
| DQS: 53 | Scheldt | 55 | 71 | 63 | 37 | 38 | 40 |
| IJsselmeer | 32 | 96 | 60 | 29 | 33 | 31 | |
| nationally managed waters | 57 | 87 | 76 | 48 | 50 | 56 | |
| Lead | Rhine | 203 | 179 | 146 | 163 | 135 | 179 |
| MAC: 800 | Maas | 650 | 328 | 303 | 259 | 314 | 315 |
| DQS: 128 | Scheldt | 218 | 199 | 193 | 152 | 159 | 142 |
| IJsselmeer | 76 | 120 | 100 | 63 | 71 | 54 | |
| nationally managed waters | 281 | 210 | 183 | 157 | 164 | 167 | |
| Zinc | Rhine | 821 | 843 | 702 | 692 | 543 | 833 |
| MAC: 930 | Maas | 4 825 | 4 015 | 2 057 | 1 479 | 1 626 | 1 478 |
| DQS: 210 | Scheldt | 843 | 809 | 916 | 553 | 633 | 546 |
| IJsselmeer | 420 | 741 | 613 | 330 | 385 | 328 | |
| nationally managed waters | 1 600 | 1 463 | 1 032 | 744 | 768 | 759 | |
| Source: Commissie Integraal Waterbeheer | RIVM/EDC/Oct02 | ||||||
| 1) Maximum allowable concentration (MAC) and desired quality standard (DQS). | |||||||
Rectification
The figures in the printed version of the 2001 Environmental Data Compendium are not correct. The incorrect figures were also on this site for a while. The figures above are the right ones.
Development
Heavy metals combine to a greater or lesser extent with suspended matter. The concentrations of heavy metals in suspended matter in fresh surface water are decreasing over time, even if the pattern is sometimes rather unpredictable. Chromium, mercury and lead do not exceed the MAC anywhere. Cadmium, copper, nickel and zinc exceed the MAC in the River Maas . The relatively low metal levels in suspended matter are a feature of the IJsselmeer. In regionally managed waters, there is no systematic measuring of heavy metals in suspended matter.
Policy
The aim of the policy is to reduce the levels of metals to below the MAC and, in the slightly longer term, to below the DQS.
Relevance
The quality of the suspended matter determines the quality of the river, lake or sea bed. The values for the MAC are based on ecotoxicological grounds. That means that, when the MAC is exceeded, negative effects on organisms cannot be excluded.
Monitoring sites
- The monitoring sites in the rivers are sites chosen by the Commissie Integraal Waterbeheer/Commissie Uitvoering Wet Verontreiniging Oppervlaktewater (CIW/CUWVO).
- For bodies of water under national management a group of monitoring sites was compiled from 25 representative sites selected by this committee from the entire monitoring network of national water bodies. It includes sites in the Rhine, Maas, Scheldt, IJssel, IJsselmeer and in a number of canals and lakes.
