Dutch National Institute for Public Health and the Environment RIVM’s new study to know the origin of the substances deposited in IJmond region’s living environment shows that the Polycyclic Aromatic Hydrocarbons and metals present in the living environment of residents of the IJmond region predominantly originate from the Tata Steel’s IJmuidensite. This RIVM study combined the results of previous measurements with findings from scientific literature, data from the Netherlands Pollutant Release and Transfer Register, and research into the composition of the dust.The study shows that the the Polycyclic Aromatic Hydrocarbons deposited in the region mainly originate from the Tata Steel site due to1. Coke production2. Coarse dust particles becoming airborne3. Storage and transhipment of coal4. Dust that had previously settled on the Tata Steel site becoming airborne againThe metals primarily originate from the Tata Steel site due to1, Dust particles being released during the production of pellets, sinter ore and coke2. Coarse dust particles, originating from the storage and transhipment of ores and other materials, becoming airborne3. Dust that had previously settled on the Tata Steel site becoming airborne againIn this study, RIVM used two methods to determine the origin of the particulate matter PM10 in the air. The study of the composition of the particulate matter shows that two profiles originate from local sources, with emissions differing per source, meaning that the composition of the PM10 provides information about the potential source. From this RIVM deduced that the PAHs and metals mainly originate from the Tata Steel site. The second research method consisted of a comparison to determine whether the concentrations of substances identified in the air correspond to calculations based on the known emissions. This was the case for the particulate matter concentration. However, far lower levels of PAHs and metals were calculated based on the known emissions than were actually measured. Due to this significant discrepancy, RIVM was unable to properly determine the origin of substances in the air. RIVM did not examine the causes of this discrepancy. RIVM advised authorities, that if they require more precise identification of the origin of the substances present in the air in the IJmond region, to take steps to collect more detailed data on the emissions of PAHs and metals. In addition, RIVM advises taking measurements aimed at identifying sources to monitor the deposition of PAJ and metals in the environment of the Tata Steel site. Collecting more precise measurement data will enable taking the right measures at the source, and is a key factor to be able to monitor whether measures taken with a view to reducing the presence of substances in the living environment are effective. This is the third and final study into substances and health in the IJmond region. The study was conducted on behalf of the province of North Holland and the Municipalities of Beverwijk, Heemskerk and Velsen. In 2021, RIVM already concluded that the levels of PAHs and lead in the dust deposited in the living environment were undesirable from a health perspective, particularly when it comes to children’s health. RIVM previously concluded that more acute symptoms are reported to general practitioners in the IJmond region and that the air quality is frequently moderate to unsatisfactory. The findings of the present study have not had any impact on these conclusions. The three studies jointly provide answers to residents’ questions about the impact of substances present on the quality of their living environment.