A drill echoes through narrow tunnels deep within the mountain where miner Hugo Flores bores into rock in search of one of Earth’s most toxic elements. Buried in red stripes of minerals illuminated by his headlamp is mercury. Here in the pine-covered mountains known as the Sierra Gorda – one of the most biodiverse stretches of Mexico – a “mercury boom” is underway. Soaring international gold prices are driving up the price of mercury, a toxic metal key in illegal gold mining, to all-time highs. While the demand triggers a mining rush in central Mexico, sustaining thousands of miners and their families, it also ... (full story)