There are two updates to APIS to be aware of. Data updates can be found on the APIS update log here.
On 06 June 2019 the background deposition and concentration datasets were updated to a 3-year average for 2015-2017. These are used in the Search by Location and Site Relevant Critical Loads tools background pollution maps. See http://www.apis.ac.uk/update-log for details.
On 05 August 2019 a correction was implemented for critical loads of W7 woodland on Areas/Sites of Special Scientific Interest (A/SSSIs). This applies to National Vegetation Class (NVC) W7 Woodland - Broad-leaved, mixed and yew woodland (Alnus glutinosa - Fraxinus excelsior - Lysimachia nemorum woodland) only on A/SSSIs. For European Sites, W7 woodland was showing as not sensitive to nitrogen deposition but on A/SSSIs a critical load was present. The error has now been rectified and both A/SSSIs and European Sites show W7 woodland as not being sensitive to Nitrogen Deposition. The evidence for this is in the Nitrogen Decision Framework documentation. On the Factor 1 Spreadsheet, Line 119, W7 woodland is not sensitive to Nitrogen Deposition. Column G shows the NVC. http://archive.jncc.gov.uk/default.aspx?page=6272 Please note, W7 woodland is however grouped in with alluvial woodland and these NVC classes overlap with Wet Woodland classes considered sensitive to Nitrogen Deposition (eg W2 and W5). As such, where alluvial woodland is referenced, confirmation of W7 woodland presence at site level is important to inform risk assessment.