North Korea conducted its sixth nuclear test on Sept. 3, prompting theUN Security Council to step up sanctions with a ban on the reclusive regime's textile exports and a cap on fuel imports. Read more.
Radioactive contamination following a nuclear power-plant disaster in Japan never reached unsafe levels in the north Pacific Ocean for either marine life or human health, says a British Columbia scientist.
Chemical oceanographer Jay Cullen of the University of Victoria has monitored levels of contamination from radioactive isotopes, used in cancer therapies and medical imaging, since the meltdown of three reactors at the Fukushima Daiichi plant in 2011 following a tsunami triggered by an earthquake. Read more.