When a group of Danish ninth graders experienced difficulty concentrating after sleeping with their cell phones by their head, they performed an experiment to test the effect of wireless Wi-Fi routers on garden cress. One set of plants was grown in a room free of wireless radiation; the other group grew next to two routers that released the same amount of radiation as a cell phone. The results? The plants nearest the radiation didn’t grow. 
RESULTS: Our data showed that the weight gain in the WI-FI exposed group was significantly lower than the control group (p<0.05). Wi-Fi (2.45 GHz) exposed group showed hyperglycemia. Plasma insulin level and glucose-stimulated insulin secretion from pancreatic islet were significantly reduced in the Wi-Fi exposed group. EMR emitted from Wi-Fi caused a significant increase in lipid peroxidation and a significant decrease in GSH level, SOD and GPx activities of the pancreas.
Microwave News’s Slesin speculated on potential explanations for the NTP’s apparent backtracking: new leadership within the program, where a former drug-company executive, Brian Berridge, now runs the day-to-day operations; pressure from business-friendly Republicans on Capitol Hill and from the US military, whose weapons systems rely on wireless radiation; and the anti-science ideology of the Trump White House. The question now: Will the scientists doing the peer review endorse the NTP’s newly ambivalent perspective, or challenge it?51
The most compelling evidence though comes from a Swedish team of cancer experts whose research stretches back 15 years. The results clearly demonstrate “a consistent association between long-term use of cell phone and cordless phones and glioma and acoustic neuroma”. Overall, they found that using a cell phone for more than a decade significantly increases the risk of a malignant tumour by almost two times with an analogue cell phone and by nearly four times with a digital phone. Interestingly, the risks were even higher for people who had started using mobiles as teenagers.