Calls are being made to a charity helpline every hour by adults concerned about alcohol or drug use around children.
Figures from the NSPCC show 8,500 people from across the UK contacted the charity last year to describe potential substance misuse amongst adults when children and young people were in their care or nearby - an average of almost one contact every hour.
The number is up by 16% since 2013/14, when just over 7,300 people got in touch, the children's charity said.
Over the last three years the focus of more than 25,000 calls to the NSPCC helpline has been children's exposure to alcohol, drugs and other substances.
The helpline is a free and confidential service that adults can contact by phone or online to get advice or share their concerns about a child.
Some contacts have been judged so serious that the charity has made more than 20,000 referrals to external agencies, including the police and children's services, about substance abuse around children in the past three years.
The figures have been released at the start of Children of Alcoholics Week, which aims to raise awareness of the problems and suffering associated with parental alcohol problems.
NSPCC chief executive, Peter Wanless, said: "Drug and alcohol abuse can have hugely damaging effects around children and it's clearly troubling to see a rise over time in reports of this problem to our helpline.
"Substance misuse all too often leads to the neglect or abuse of a child and it's absolutely crucial that we do all we can to stop that.
"The NSPCC provides services directly to families suffering from these problems to help them overcome them and provide their children with a safe and secure upbringing.
"But everyone has a duty to look out for potential signs of distress and the NSPCC's helpline is there to provide help and support 24 hours a day, 365 days a year."