I tīpakohia te maitai paerewa o ngā peera pōro, he nui te waro me te chromium, ā, i whakapakeketia kia tu atu i te pēhanga nui i waenga i te huānga hurihuri me ngā mowhiti peera.
Ko te whakamārō i ngā mowhiti o roto, o waho hoki he tukanga whakapakeke taketake mō te maha o ngā kaiwhakarato peera pōro TPI. Mā tēnei maimoatanga wera motuhake, ka piki ake te pakeke o te mata o te ara reihi; ka whakaitihia te kakahu.
Kei te wātea te maitai tino ma i roto i ētahi o ngā raupapa hua peera pōro paerewa a TPI i nāianei, nō reira ka nui ake te ātete ki te kakahu. Nā te mea he maha ngā wā ka puta te ngenge o te pa mai i ngā whakaurunga mārō kore-whakarewa, me tino ma ngā peera i ēnei rā.