Do you happen to have a link to or title of that study? I'd like details on this.
A DDG (DuckDuckGo, my go-to search engine) search for 'artificial plants lead' found only one remotely relevant link on the first two pages of hits (https://rtkenvironmental.com/healthy...ristmas-trees/) but it is a commercial site and the links it contains are of questionable quality. Google found this (https://pubmed.ncbi.nlm.nih.gov/15628192) which only talks about PVC Xmas trees.
A DDG search for 'plastic plants lead' found only one relevant page (https://www.cdc.gov/nceh/lead/preven...r-products.htm) that calls into question all plastic products, not just plants. Google found that same NIH study I linked above.
A Google scholar search for those two phrases came up empty on the first couple pages of results.
A little poking around suggests that while some fake plants are made of PVC, others are made of polyethylene or polyester (https://www.nytimes.com/wirecutter/r...t-fake-plants/). Apparently lead might be used to soften PVC; happily, it seems not to be used in PVC foam sheets (https://www.acmeplastics.com/expanded-pvc-foam).