Isu tiri inyanzvi kambani yakatarisana neyakasanganiswa quartz kugadzira pamusoro pemakore gumi.
Kubva zvakavambwa muna1999, pamusoro pe100 PSA Zvidyarwa, kusanganisira makuru epasirese epasi-imwe seti yeVPSA-CO uye VPSA-O2 zvishandiso, zvakagadzirwa uye zvinopihwa naPIONEER.