Insight into sources of dust
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This graph shows the average dust deposition of three measuring locations in Wijk aan Zee. The graph gives a grouped representation of the distribution of the origin of the dust that we find in our environment. The width of the columns represents the biweekly measurement period during which dust is collected. The height of the columns represents the amount of dust that fell into the receptacles during that period. The dust types are grouped for convenience and represent the origin of the dust source: red/black is mainly a source from our site, orange for mixed sources, green for salt, yellow for soil/sand sources and beige for other environmental sources. RIVM conducted a total of three measurement campaigns, with each measurement campaign covering three periods of 17-18 days each. The last two RIVM measurement campaigns in spring & autumn 2022 are shown in grey as DFG and HJK.
RIVM measures the deposition of elements such as iron, manganese and vanadium, but not the total quantities of substances or those of individual sources of substances. We find more dust deposition related to sources on our site in the periods where RIVM measured in the autumn of 2022 (HKJ) than in the spring (DFG). This is consistent with RIVM's view that there was more deposition of iron, manganese, vanadium and chromium in that period—elements that we know are related to sources on our site, such as iron ore and slag. Higher dust deposition from these dust sources in 2022 was only measured in Wijk aan Zee during the storm season in the spring with our own monitoring. The measurements show that the amount of dust deposited is dependent on the weather; we also find more dust in that measurement period during storms or strong winds. With a whole calendar year of measurements, it is clear that there is a great deal of fluctuation in dust deposition and that it takes a long time to measure to see structural changes. That is why we started this continuous monitoring of dust deposition. We will continue to do this so that we also gain more insight into the effectiveness of measures taken to reduce emissions and the impact on the living environment.