Mgbe achọpụtara ọkwa dị elu nke molybdenum trace element (mah-LIB-den-um) n'olulu mmiri ọñụñụ dị na ndịda ọwụwa anyanwụ Wisconsin, ọtụtụ ebe a na-ekpofu unyi na mpaghara ahụ yiri ka ọ bụ isi iyi nke mmetọ ahụ.

Mana ụfọdụ ọrụ nyocha mara mma nke ndị nyocha sitere na Mahadum Duke na Mahadum Ohio State na-eduzi ekpughere na ọdọ mmiri ndị ahụ, bụ́ ndị nwere ihe mkpofu nke coal a na-ere ọkụ na ụlọ ọrụ ọkụ, abụghị isi iyi nke mmetọ ahụ.

O sitere na isi mmalite nke eke kama.

"Dabere na ule site na iji forensic isotopic 'mkpịsị aka' na usoro mmekọ nwoke na nwanyị, nsonaazụ anyị na-enye ihe akaebe nke onwe ya na uyi coal abụghị isi iyi nke mmetọ na mmiri," Avner Vengosh, prọfesọ nke geochemistry na àgwà mmiri na Duke's Nicholas School of kwuru. Environment.

Vengosh kwuru, "Ọ bụrụ na mmiri a nwere molybdenum bara ụba sitere na nsị nke coal ash, ọ ga-adị obere, ebe a na-ebunye ya n'ime mmiri mmiri dị n'ime ala site na ntụ ntụ n'elu naanị afọ 20 ma ọ bụ 30 gara aga," Vengosh kwuru. "Kama, ule anyị na-egosi na ọ si n'ime ala dị omimi ma bụrụ ihe karịrị afọ 300."

Nlele ndị ahụ kpughekwara na akara mkpịsị aka isotopic mmiri ahụ emeru—ọnụego ya nke boron na strontium isotopes— adabaghị na mkpisi aka isotopic nke ihe mkpofu ọkụ.

Nchoputa ndi a "de-link" molybdenum sitere na ebe a na-ekpofu uyi unyi kama na-egosi na obu ihe sitere na usoro okike na-eme na matrix aquifer's rock matrix, Jennifer S. Harkness, onye nyocha postdoctoral na Ohio State nke duziri ihe omumu a dika akuku. nke nzere doctoral ya na Duke.

Ndị nchọpụta ahụ bipụtara akwụkwọ nyocha nke ndị ọgbọ ha n'ọnwa a na magazin Environmental Science & Technology.

Obere molybdenum dị mkpa maka ma anụmanụ ma ndụ osisi, mana ndị na-eri oke n'ime ya na-enwe nsogbu nke gụnyere anaemia, mgbu nkwonkwo na ịma jijiji.

Ụfọdụ n'ime olulu mmiri ndị a nwalere na ndịda ọwụwa anyanwụ Wisconsin nwere ihe ruru 149 micrograms nke molybdenum kwa lita, nke dị ntakịrị karịa okpukpu abụọ ụkpụrụ ọkwa mmanya dị mma nke Òtù Ahụ Ike Ụwa, nke bụ 70 micrograms kwa lita. Ụlọ ọrụ na-ahụ maka gburugburu ebe obibi nke US na-esetịpụ oke ọbụlagodi na 40 micrograms kwa liter.

Iji duzie ọmụmụ ihe ọhụrụ ahụ, Harkness na ndị ọrụ ibe ya jiri ndị nyocha nyocha iji chọpụta oke nke boron na strontium isotopes na nke ọ bụla n'ime nlele mmiri. Ha tụkwara ihe nlele nke ọ bụla tritium na helium radioactive isotopes, nke nwere ọnụ ahịa ire ere mgbe niile ma enwere ike iji ya nyochaa afọ afọ, ma ọ bụ “oge obibi” na mmiri dị n'ime ala. Site n'ijikọta usoro nchọpụta abụọ a, ndị ọkà mmụta sayensị nwere ike ịchịkọta ozi zuru ezu banyere akụkọ ihe mere eme nke mmiri dị n'ime ala, gụnyere mgbe mbụ ọ banyere n'ime mmiri aquifer, na ụdị nkume ndị ọ na-emekọrịta ihe na oge.

"Nnyocha a gosipụtara na mmiri molybdenum dị elu esiteghị na ntụ ntụ nke dị n'elu, kama ọ sitere na mineral bara ụba nke molybdenum na matrix aquifer na ọnọdụ gburugburu ebe obibi na mmiri miri emi nke nyere ohere maka ịhapụ molybdenum a n'ime mmiri. mmiri dị n'ime ala," Harkness kọwara.

"Ihe pụrụ iche banyere ọrụ nyocha a bụ na ọ na-ejikọta ụzọ abụọ dị iche iche-mkpịsị aka isotopic na afọ ndụ-n'ime otu ọmụmụ," ka o kwuru.

Ọ bụ ezie na ọmụmụ ihe ahụ lekwasịrị anya na olulu mmiri ọṅụṅụ na Wisconsin, nchoputa ya nwere ike ịdaba na mpaghara ndị ọzọ nwere ọdịdị ala ndị yiri ya.

Thomas H. Darrah, osote prọfesọ nke sayensị ụwa na Ohio State, bụ Harkness's postdoctoral advisor na Ohio State ma bụrụkwa onye na-ede akwụkwọ nke ọmụmụ ọhụrụ ahụ.