Ilimin yanayi na muhalli

**Ilimin yanayin muhalli** fanni ne na kimiyya da yawa da ke da alaƙa da nazarin illolin da ke tattare da nau'ikan sinadarai, ƙwayoyin halitta da na zahiri akan rayayyun halittu. Ecotoxicology wani yanki ne na ilimin kimiyyar muhalli wanda ya shafi nazarin illolin masu sa maye a yawan jama'a da matakan muhalli.

Ana daukar Rachel Carson a matsayin mahaifiyar ilimin kimiyyar muhalli, yayin da ta mai da shi wani fanni na musamman a cikin toxicology a cikin 1962 tare da buga littafinta na Silent Spring, wanda ya rufe tasirin amfani da magungunan kashe qwari. Littafin Carson ya dogara da yawa akan jerin rahotannin Lucille Farrier Stickel akan illolin muhalli na DDT mai kashe qwari.

Za a iya fallasa kwayoyin halitta ga nau'ikan abubuwan maye a kowane mataki na rayuwa, wasu daga cikinsu sun fi wasu hankali. Har ila yau guba na iya bambanta tare da sanya kwayoyin halitta a cikin gidan yanar gizon abinci. Bioaccumulation yana faruwa ne lokacin da kwayoyin halitta ke adana abubuwan maye a cikin kyallen takarda, wanda a ƙarshe zai iya kafa kaske na trophic da biomagnification na takamaiman abubuwan maye. Biodegradation yana fitar da carbon dioxide da ruwa a matsayin abubuwan da ke cikin muhalli. Wannan tsari yawanci yana iyakance ne a wuraren da abubuwan da ke damun muhalli suka shafa.

Mummunan illolin irin waɗannan sinadarai da ƙwayoyin halitta kamar su masu guba daga gurɓatattun abubuwa, magungunan kashe qwari, magungunan kashe qwari, da takin zamani na iya shafar kwayoyin halitta da al’ummarta ta hanyar rage bambancin nau’insa da yalwar su. Irin waɗannan canje-canjen a cikin haɓakar yawan jama'a suna shafar yanayin muhalli ta hanyar rage yawan aiki da kwanciyar hankali.

A kowane mataki, waɗannan gubar na iya haifar da mummunar illa ga lafiyar jiki kamar rashin lafiyar jiki, ciwon ciki da gudawa, da mutuwa.

Kodayake dokokin da aka aiwatar tun farkon shekarun 1970 sun yi niyya don rage cutar da abubuwan maye gurbi a kan kowane nau'in, McCarty (2013) ya yi gargadin cewa "ƙaddarar da aka daɗe a cikin aiwatar da ƙirar ra'ayi mai sauƙi wanda shine tushen ka'idojin gwajin guba na ruwa na yanzu" na iya haifar da haɗarin muhalli mai zuwa "shekarun duhu".

Manufofin gudanarwa game da gubar muhalli

## Manufofin Amurka
Don kare muhalli, an rubuta Dokar Kare Muhalli ta Kasa (NEPA). Babban abin da NEPA ta fito fili shi ne, “tana ba da tabbacin cewa dukkan sassan gwamnati suna ba da la’akari da yanayin da ya dace kafin aiwatar da wasu manyan ayyuka na tarayya da suka shafi muhalli sosai.” An zartar da wannan doka a shekarar 1970 kuma ta kafa Council on Environmental Quality (CEQ). Muhimmancin CEQ shi ne cewa ya taimaka kara tura yankunan manufofin.

CEQ ta ƙirƙiri shirye-shiryen muhalli da suka haɗa da Dokar Kula da Gurbacewar Ruwa ta Tarayya, Dokar Kula da Abun Mai Guba, Dokar Kare Albarkatu da Farfaɗowa (RCRA da Safe). CEQ yana da mahimmanci wajen ƙirƙirar tushe ga yawancin "dokokin muhalli na yanzu ban da Superfund da dokokin sarrafa asbestos."

Wasu illolin farko na NEPA sun shafi fassarar cikin Kotuna. Ba wai kawai Kotuna ta fassara NEPA don faɗaɗa tasirin muhalli kai tsaye daga kowane ayyuka, musamman na tarayya ba, har ma da ayyukan kai tsaye daga ayyukan tarayya.

### Dokar Kula da Abu Mai Guba
TSCA, wanda kuma aka sani da Dokar Kula da Abubuwan Guba, wata doka ce ta tarayya wacce ke tsara sinadarai na masana'antu waɗanda ke da yuwuwar cutar da mutane da muhalli. TSCA na musamman ya yi niyya "ƙira, shigo da kaya, ajiya, amfani, zubarwa, da lalata sinadarai a cikin amfani da kasuwanci." EPA ta ba da izinin yin haka: "1. Gwajin gwajin farko na sinadarai don ƙayyade lafiyar lafiya ko haɗarin muhalli 2. Binciken sunadarai don babban haɗari kafin fara samar da kasuwanci 3. Ƙuntatawa ko haramtawa a kan wasu masana'antun sarrafa kayan aiki ko fitarwa 4. shiga ko barin Amurka."

### Dokar Tsabtace Iska
An taimaka wa Dokar Tsabtace Jirgin Sama ta hanyar sanya hannu kan gyare-gyaren 1990. Waɗannan gyare-gyaren sun kare rage acid, Layer ozone, inganta ingancin iska da gurɓata mai guba. An sake sake fasalin Dokar Tsabtace Jirgin Sama kuma tare da goyon bayan Shugaba George H.W Bush, an sanya hannu a ciki. Babban manyan barazanar da wannan aikin ya yi niyya shine: gurɓataccen iska na birane, iskar gas mai guba, sararin samaniyar ozone, ruwan sama na acid da sauransu. Baya ga yin niyya ga waɗannan takamaiman wurare, ya kuma kafa wata ƙasa mai aiki da "ba da izinin shirin yin doka mafi aiki, da ƙarfafa tilasta aiwatarwa don taimakawa wajen tabbatar da ingantaccen bin doka."

## Manazarta