Kev tsim kho ntawm science thiab thev naus laus zis tau txhawb kev txhim kho ntawm tib neeg' s lub neej nyob, thiab kev paub ntawm kev saib xyuas tus kheej tseem ua haujlwm tau nce ntau. Hauv lub neej txhua hnub, kev siv" kev nyab xeeb" thiab" noj qab nyob zoo" cov khoom lag luam yog qhov kev txhawj xeeb tshaj plaws ntawm cov neeg niaj hnub. Cov neeg niaj hnub nyob hauv nroog uas nrhiav kev noj qab haus huv thiab lub neej zoo yog nce siv cov yeeb nkab steel hlau, polyethylene thiab lwm cov kav dej ntsuab.
Qhov ua tau zoo ntawm cov dej haus thiab kav dej yog ib qho ntawm cov ncauj lus txhawj xeeb tshaj plaws. Cov kav hlau hlau feem ntau tsis yooj yim rau xeb, xeb, dej xeb, thiab ua rau tawg. Yog li no, qhov tsawg dua xeb, tsis muaj xeb, tsis muaj xau, thiab tsis muaj qhov yam ntxwv ntawm qhov hluav taws xob qhuav ntawm cov yeeb yaj kiab yuav ua kom haum cov neeg nyiam. Qee lub tebchaws tsim tseem tau tsim txoj cai lij choj txwv tsis pub siv cov kav dej ntawm cov kav dej galvanized li cov kav xa dej.
Cov kav dej ntsuab xws li cov yeeb nkab steel hlau tau muag ncaj qha rau hauv kev zam, thiab ob qho tib si ntau lawm thiab muag ntau yam ntxiv. Qee cov khoom lag luam tseem nyob tsis txaus thiab ua qhov kev loj hlob tshiab rau kev lag luam hauv lub teb chaws. Raws li kev soj ntsuam kev lag luam, kev tsim tawm ntawm cov kav dej ntsuab tau nce siab tshaj plaws sai sai hauv xyoo 2002 thiab 2003, thiab kev siv cov khoom siv cia siab tshaj li 3.5 lab tons.
