Scientists at the Experimental Lakes Area in northwestern Ontario began adding synthetic estrogen 17α-ethynylestradiol (EE2) to Lake 260 in May 2001. ^[1] The fathead minnow population in Lake 260 collapsed in fall 2002, largely because young-of-the-year fish had disappeared. ^[2] By 2013, the treated watershed was exporting 30 times more inorganic nitrogen into its streams than nearby untreated forest catchments. ^[3] In October and November 1999, researchers spread approximately 45 short tons (40 metric tonnes) of pelletised wollastonite over a 29-acre (11.8-hectare) catchment in the White Mountains of New Hampshire to replace calcium lost to acid rain. ^[4] A study published in the Proceedings of the National Academy of Sciences in 2026 by researchers at Upstate Medical University found that aging significantly limits the ability of retinal glia to be reprogrammed into new neurons. ^[5] Levi Todd, Ph.D., of Upstate Medical University, said in 2026 that the field of glial reprogramming has grown rapidly since the 2017 discovery that new retinal neurons could be generated from glia, but that growth has focused almost entirely on refining techniques in young animals. ^[6] The study showed that dampening the immune system with anti-inflammatory steroids could partially restore the retina's regenerative response in aged neurons. ^[7] Todd said in 2026 that the efficiency of glial-to-neuron reprogramming is largely reduced with age, and he pointed to two underlying factors: cells become 'tired' and lose plasticity, and inflammation increases with age due to blood-brain barrier breakdown. ^[8]