I ka wā i ʻike ʻia ai nā pae kiʻekiʻe o ka trace element molybdenum (mah-LIB-den-um) i loko o nā pūnāwai wai inu ma ka hikina hema o Wisconsin, ua ʻike ʻia ka nui o nā wahi hoʻolei lanahu o ka ʻāina i ke kumu o ka haumia.

Akā, ua hōʻike ʻia kekahi mau hana kiʻi maikaʻi i alakaʻi ʻia e nā mea noiʻi mai ke Kulanui ʻo Duke a me The Ohio State University ʻaʻole nā ​​loko i loaʻa nā koena o ka lanahu i puhi ʻia i nā mea kanu mana, ʻaʻole ia ke kumu o ka haumia.

No nā kumu kūlohelohe ia.

"Ma muli o nā ho'āʻo e hoʻohana ana i ka forensic isotopic 'fingerprinting' a me ka makahiki-dating techniques, ua hāʻawi kā mākou mau hopena i nā hōʻike kūʻokoʻa ʻaʻole ʻo ka lehu lanahu ke kumu o ka haumia i ka wai," wahi a Avner Vengosh, ke kaukaʻi o ka geochemistry a me ka maikaʻi o ka wai ma Duke's Nicholas School of ke Kaiapuni.

"Inā loaʻa kēia wai waiwai nui i ka molybdenum mai ka hoʻolele ʻana o ka lehu lanahu, he ʻōpiopio paha ia, ua hoʻihoʻi ʻia i loko o ka wai wai o ka ʻāina mai nā waihona lehu lanahu ma ka ʻili he 20 a i ʻole 30 mau makahiki i hala," wahi a Vengosh. "Ma kahi o kā mākou hōʻike hōʻike ʻana mai ka hohonu o lalo a ʻoi aku ma mua o 300 mau makahiki."

Ua hōʻike pū ʻia nā hoʻāʻo ʻana ʻaʻole i kūlike ka manamana lima isotopic o ka wai i hoʻohaumia ʻia-ʻo kona mau lakio pololei o ka boron a me strontium isotopes-ʻaʻole i kūlike me nā manamana lima isotopic o nā koena puhi lanahu.

ʻO kēia mau ʻike "de-link" i ka molybdenum mai nā kahua hoʻolei lehu lanahu a ke manaʻo nei ʻo ia ka hopena o nā kaʻina hana kūlohelohe i hana ʻia i loko o ka pōhaku pōhaku o ka aquifer, wahi a Jennifer S. Harkness, kahi mea noiʻi postdoctoral ma Ohio State nāna i alakaʻi i ke aʻo ʻana ma ke ʻano he ʻāpana. o kana palapala kauka kauka ma Duke.

Ua paʻi ka poʻe noiʻi i kā lākou pepa i nānā ʻia e nā hoa i kēia mahina ma ka puke pai Environmental Science & Technology.

He mea nui ka liʻiliʻi o ka molybdenum i ke ola holoholona a me nā mea kanu, akā ʻo ka poʻe e ʻai nui i ia mea e pilikia ai nā pilikia e pili ana i ka anemia, ka ʻeha a me ka haʻalulu.

ʻO kekahi o nā pūnāwai i hoʻāʻo ʻia ma ka hikina hema o Wisconsin aia a hiki i ka 149 micrograms o ka molybdenum no ka lita, ʻoi aku ma mua o ka pālua o ka pae inu palekana o ka World Health Organization, ʻo ia ka 70 micrograms i ka lita. Hoʻonohonoho ka US Environmental Protection Agency i ka palena ma lalo o 40 micrograms no ka lita.

No ka hana ʻana i ka noiʻi hou, ua hoʻohana ʻo Harkness a me kāna mau hoa hana i nā tracers forensic e hoʻoholo ai i ka ratio o ka boron i ka strontium isotopes i kēlā me kēia o nā ʻano wai. Ua ana nō hoʻi lākou i ka tritium a me ka helium radioactive isotopes o kēlā me kēia laʻana, i loaʻa ka nui o ka pohō mau a hiki ke hoʻohana ʻia e loiloi i ka makahiki o kahi hāpana, a i ʻole "manawa noho" i loko o ka wai lepo. Ma ka hoʻohui ʻana i kēia mau pūʻulu ʻike ʻelua, ua hiki i nā ʻepekema ke hōʻuluʻulu i ka ʻike kikoʻī e pili ana i ka mōʻaukala wai o ka honua, me ka wā i komo mua ai i loko o ka wai, a me nā ʻano pōhaku i launa pū me ia i ka wā lōʻihi.

"Ua hōʻike ʻia kēia hōʻike ʻana ʻaʻole i hoʻokumu ʻia ka wai molybdenum kiʻekiʻe mai ka waiho ʻana o ka lehu lanahu ma luna o ka ʻili, akā ma muli o nā minerala waiwai nui o ka molybdenum i loko o ka aquifer matrix a me nā kūlana kaiapuni i ka aquifer hohonu i hiki ai ke hoʻokuʻu ʻia kēia molybdenum i loko o ka wai. wai lepo," i wehewehe ʻo Harkness.

"ʻO ka mea ʻokoʻa e pili ana i kēia papahana noiʻi ʻo ia ka hoʻohui ʻana i ʻelua mau ʻano like ʻole - nā manamana lima isotopic a me ka makahiki-dating-i loko o hoʻokahi haʻawina," wahi āna.

ʻOiai ua pili ka haʻawina i nā pūnāwai wai inu ma Wisconsin, hiki ke hoʻohana ʻia kāna mau ʻike i nā wahi ʻē aʻe me nā geologies like.

ʻO Thomas H. Darrah, ka hoa kaukaʻi o ka ʻepekema honua ma Ohio State, ʻo ia ka ʻōlelo aʻoaʻo postdoctoral o Harkness ma Ohio State a ʻo ia kekahi mea kākau o ka noiʻi hou.