Pesticides and exposure to chemicals in paint and solvents are also said to be behind the rise in the number of children being diagnosed with the disease.
Figures show that 151 children in Scotland were treated for cancer in 2016, compared with 112 in 2007 - a rise in 34 percent.
Parents are experts are calling for more robust research into the causes of childhood cases with leukaemia the most common form of the disease in the young.
Dr Henshaw said warnings over the links between air pollution and the disease were ignored by the UK Government when it introduced tax breaks for diesel car owners.
He told The Sunday Post newspaper: "The first warnings linking poor health were given in the 1990s but the government gave diesel car owners tax breaks in 2001.
"We were shocked to see the figures, and it's the modern lifestyle I am afraid.
"Many items on the list of environmental causes are now known to be carcinogenic, such as air pollution and pesticides and solvents.
"Leukaemia is by far the most common childhood cancer and the links are environmental/
Dr Henshaw, professor of human radiation effects at Bristol University, said: "What is worrying is it is very hard to avoid a lot of these things. How can you avoid air pollution?"
A study by Swiss scientists found that children who live near a motorway have a higher risk of leukaemia. Their research found that children who live within 100 metres of a motorway had a 47 % to 57% higher risk of contracting leukaemia with a link drawn between exhaust fumes and the disease.
Father Paul Whiteford, 33, of Fort William, whose son Ryan, six, was diagnosed with leukaemia when aged just three-years-old, said an investigation into the rise of Scottish cases was urgently required.
He told the newspaper: "Ryan was unwell with ear infections before he was diagnosed and some medical research suggests this may trigger leukaemia in rare cases.
"However, serious questions arise over what we are doing to our planet and how much pollution and pesticides contribute. Do they cause genetic mutations which make us more susceptible?
"It is a grey are which needs urgent attention. Our great fear is that our other children will develop it. It's a natural worry for any parent of a child with cancer."
He said that his son Ryan is on maintenance chemotherapy and hopes to be treatment-free in January.
The Children's Cancer and Leukaemia Group, which is made up of child cancer professionals, told the newspaper that better recording of the disease in the young should be factored into the rise in Scottish cases - but that real increases in diagnosis had been recorded.
A spokesman said: "The cancer incidence in children, teenagers and young adults has risen but it remains a rare disease.
"Some of it is because of better recording but also a real rise in numbers.
"There is an increasing body of evidence pointing to air pollution, particularly from traffic, as a risk factor for childhood cancer and particularly acute lieukaemias.
"But more research needs to be done to establish greater definitive links."
Slightly increased incidences in childhood leukaemia were found in those whose parents had been exposed to paint and pesticides before conception, through pregnancy or after birth.
"They suggest a link but are non conclusive," the spokesman added.
Figures from the Soil Association show that the number of active substances- or chemicals - applied to the three major crops of wheat, onions and potatoes increased between three and 11 times between the 1970s and 2015.
A spokesman for The Scottish Government said: "We are committed to improving children's cancer services.
"We are working hard to ensure health professionals have and can achieve appropriate skills in child health and paediatrics."
For more information, visit: https://www.childrenwithcancer.org.uk/