Environmental testing began Saturday morning at a New Jersey high school amid concerns there could be a cancer cluster associated with the school.

The testing came about when a former student at Colonia High School in Woodbridge stricken with brain cancer got suspicious. His sister and wife, who both went to the school, also ended up with a similar diagnosis.

He then discovered through social media that nearly 100 other former students and staff have had brain cancer.

The township approved at least $450,000 for a private environment firm to carry out the testing.

On Saturday morning, equipment was being used inside and outside the school to check for elevated levels of radiation.

Woodbridge Mayor John E. McCormac says testers will be leaving “canisters” around the school for two weeks, then collect and analyze data to “determine if there's any issues with the air quality inside."