The experiments on humidification desulfurization by high calcium coal ash were carried out at a thermo balance and a semi industrial test ring.

But because of hard to fix test ring in bedrock, so report of domestic deep worked-out area overlying rock subsidence observation by layers have not yet been heard so far.

When people ring, they are often told about clinics outside their immediate community; in future they will be offered special test kits they can use at home.