Olivia Newton-John was involved in many of Children's Health Environmental Coalition's (CHEC) activities in the early 2000s, and was CHEC's National Spokesperson for over a decade. Olivia was presented with an award for her services to CHEC in 2004.
CHEC was established in 1992 after the death of Colette Chuda who died of a non-hereditary form of cancer, Wilm’s tumor. Colette the young daughter of James and Nancy Chuda, Olivia's friends.
Colette is the girl on the right on the picture on Olivia's Warm and Tender album
Their website was at http://www.checnet.org - you can see a copy at the Internet Archive
CHEC's goal
Our ultimate goal is to eliminate children's exposure to man-made toxic substances by ensuring everyone’s right-to-know what is in their air, food, water and commercial products. We are working to achieve this goal through increased scientific research, government policies which are more protective of children, and educating and mobilizing individuals — like you — around the country.
At some point this work appears to have been subsumed into Healthy Child https://healthychild.org/, also established by the Chudas in 1992