Mailbox - artificial sand in Manila Bay

This is the section of the show where we address your correspondence. Razel is from the Philippines, and is asking about some news about the “white sand of controversy” in Manila Bay - where an artificial beach project using dolomite rocks has been criticised for being an environmental hazard. He asks: “what is the science around Dolomite sand, and does it have health related risks?”

Adam - Well our very own Phil Sansom has been looking into this, and he explained that dolomite is a naturally-occurring type of rock that’s closely related to limestone - it’s a sort of calcium-magnesium carbonate. In this case it’s coming from a large dolomite quarry on a southern Philippine island, and since August has been travelling on ships in crushed form up to Manila.

This is part of a rehabilitation programme to clean up the notoriously polluted bay - or at least, clean up its image. But the Philippines Department of Health have warned of respiratory risks if you inhale aerosolized dolomite dust, and as Bored Chemist pointed out on our forum, people and the waves will probably crush the rocks down to dust over time. Others warn of damage to the bay ecosystem from heavy metals leeching into the water.

There’s limited evidence around dolomite dust’s health or environmental risks in particular, but perhaps this is a relevant point and worth exploring before continuing the project. We’ll be following this story and hoping for some more concrete research soon.