Gurbacewar muhalli wani lamari ne da ke haifar da datti a cikinsa, wanda ke haifar da lalata abubuwa kamar ƙasa, ruwa, iska, da haske. Wannan yana canza yanayin jiki, sinadarai da halittu na muhalli, wanda hakan zai yi illa ga lafiyar ɗan adam da sauran halittu. Gurbacewar Muhalli shine gabatar da abubuwan gurɓatawa a cikin mahalli wanda ke haifar da mummunan canji. Gurbatar yanayi na iya ɗaukar nau'ikan abubuwa masu guba ko kuzari, kamar su amo, zafi, ko haske. Gurɓatattun abubuwa, abubuwan haɗin gurɓataccen yanayi, na iya kasancewa ko dai baƙin abubuwa kuzari ko kuma gurɓatattun abubuwa masu gurɓatawa. Gurbataccen yanayi galibi ana sanya shi a matsayin tushen tushe ko gurɓataccen tushe mara tushe . A shekarar 2015, gurbatar yanayi ya kashe mutane miliyan 9 a duniya. Ci gaban masana'antu, musamman masana'antu masu gurbata muhalli kamar masana'antar sinadarai, masana'antar yadi, masana'antar kera motoci da babura, samar da ɓangaren litattafan almara da takarda, samar da kayan gini, yumbun gilashi; sarrafa katako Ci gaban tattalin arziki shine babban abin da ke haifar da gurbatar ruwa.