Experts had been particularly worried about a spike in thyroid cancer, since iodine released in nuclear accidents is absorbed by the thyroid, especially in children.

NPR: WHO: Small Cancer Risk After Fukushima Accident

The recent spate of accidents in the garment trade, especially in Bangladesh, where in addition to the building collapse more than 100 have also died in factory fires over the past year has led labor unions and worker-safety groups to press Western retailers to tighten oversight of their supply chains.

WSJ: 3 Die in Cambodia Factory Collapse

But more than that, Hopkins's father was the author of A Handbook of Average and A Manual of Marine Insurance, both standard reference books for negotiating, averaging, and adjusting the liabilities to insurance underwriters of cargo losses and shipwrecks, so Hopkins grew up in a world wet with marine accidents and was especially attentive to them.

NPR: Excerpt: 'Exiles'

Most often, the guardians' job is to dispense first aid, since in a wheeled crowd of this size, accidents do occur, especially as La Septima narrows into the city centre and the historic La Candelaria district, turning Ciclovia into a kilometres-long peloton.

BBC: Reclaiming the streets in Bogota