The sand is sand that coated a bait ball water disinfectant, but there is no danger to the people. The drug coating is gradually dissolved and activity for 3 months.
Abate sand dunes coated with a drug to kill mosquito larvae. But no harm to people The drug coating is melted phased out and the effect lasted three months.
Sand tooltip is sand coated drugs to kill mosquito larvae, but no harm on the medication coating will gradually dissolve out and has the effect of long 3 months.