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Effects 0 .. .. ... ... .. I TECHNICAL REPORT DATA {PIt-.sc wad lrrrrnrrrrmr <A the ?twrsr hjw~comyldhnpl REPORT NO PA-G30/1-73-006- -_--- /2-- TITLE ANDr~UBTITLE ?uman Health Effects of I4olybdcnum in Drinking Mater January 1979 Issuing Cate G. PERFORMING OFIGANlZAl ION CODE AUTHCRIS) '8 PERFORMlhG ORGANIZATION REPORT NO d. R. Chappell, R. K. F!eglen, F. Youre-Eraso, C. C. Solcrnons, T. A. Tsongas, P. A. Walravens, P. W. Mi iston PI SFORt*IlNG ORGANIZATION NAME AN0 A-UDAESS 10 PAOGHIL* CLEMCNTNO. Environmental Trace Substances Research Progrdm 1 CC614 Campus Box 215 11 CONTRACT:GRANT rro - _- University of Colorad3 2-803645 ~ Boulder, Colorado 80309 2. SPONSORING AGENCV NAML AN0 AOORE SS 13. TYPE OF REPORT AND PERIOD COVERED Health Effects Research Laborttory - Cinn, OH Final Report- - Office of Zesearch and Development 14. SP3NSORING AGENCV CCOE U. S. Envi ronrnental Protect ion Agewy EPA/600/10 Cincicnati, Ohio 45268 5 SUPPLLMEhlARY NOTtb Project Officer: Paul tieffernan 6 ABSTRACl Holybdenirm plays an important biological rcle as a micronutrient for plants and animals. At high levels it can be toxic to animals. While concentrations in surface tiaters are generally less than 5 ;!gMo/L, concentrations as high as 500 t:gf.lo/L have beer reported in sme drinking waters. Conccntraticns in water greater than 20 iigMo/L are a lrnos t certa i rrl y 3 rt thropogen ic. The average htiman intake via food for the United States is 170 ugtio/day while the averdge intake via drinking water is less than 5 uat.!o/day. tlhile no adverse health effects have been reported in the United States, there are reports in the Russian and Indian literature of both biochemical and clinical effects in humans at intakes rangin fro!n 1 to 10 n~Mo/day. Rapid urinary excretion appears to provide considerable tro- tection at int.ikes less than 1 mgMo/day. This report reviews the data on nolybdenum as it relates to the effects of its occurrence in drinking water. The report a153 reviews the results of an interdiscip1fr:ary study carried out by the authors. T!!e authors recommend a guideline of 50 ugKa/L for the maximurn concen- tration in drinking water. Kolybd?num, Potable water, Criteria, Health\ Colorado 60G Cherni (.a1 anal ys is , Biochemistry, Meta bo1 ism Toxicity - 8 UlSTRlBWTlON :>TATEVENT 19 SECURITV CLASS (This Kt-;wr~,- __ 71. NO. C.F PAGES ~ Unci ass if ied P.elease to Public -- I\tj 20 SECURITY CLASS (Ihispa~c) 71 PRICE , Unclasrified EPA Form 2720-1 (Re.. 4-77) Pafv.ous COITION IS OBSOLE I . .. .... SA-600/ 1-79-006 Jmilary 1979 i. HUMAN HEALTH EFFECTS OF __._- I .-__- MOLYBDENUH IN DRIMCINC WA%R 1: I. 1; iz .. -- w Willard R. Chappel1 Rokrt R. Hegler. 1 Rafael Moure-Eraso 'I Clive C. Solomons Theodora A. Tsongas i! Philip A. Walravens Paul W. Winston e3ited by Willard R. Cbcl:p11 i Robert R. Xe.3;en I / .I Environmental "race Substa:ices Research Proqram University of Colorado 1: Bouldrr, Color3do 00309 1; i, iiI i Project Officer I Paul neffernan Laboratory Studies Division Health Effects Research Laboratory Cincinnati, Ohio 45268 -! I fI- ~ - HFaTd EFFECTS RESEARCH LABOWTORY OFFICE OF RESEARCIi FCJD DEVELOPMENT -:-- .--- L' .B . EWI ROkXEXTAL PROTECT2ON AGENCY CXLIClPMATI, 01110 45268 it P'-1- - I 4-x r.;IT It 5 I E -. i I I 1' I I , -- -. I -,... 'i ,. .. .. .. ., ..,. .. I. ... .. .I ...>> . , . , .. ;_- I , . .. - ? ,. DISCLAIMER a. d’ This report .has been reviewed by the Health Effects Research Laboratory, U.S. Environmental Protection Agency, aid approved €or publication. Approval does not signify that the contents necessarily reflect the views and policies .. of thc U.S. Environmental Protection Ayency, nor does mention of trdee names <. .. ;’ or comnercial pxducts constituke endorscment or recommendation €or use. I pa I t 1 IQR3iORD i 4 ji The U.S. Envirmmental Protection Agency was created because of increas- I ing public and government concern about tne dangers of pollution to the heiiith i i and welfare of the American people. NOXLP.IC air, foul water, and spoiled land j ! are tragic testimony to the deterioration of our national environment. The t complexity of that environment and the interplay hevween its components re- ! quire a concentrated and integrated attack on the FxoL;.?m. Research and dekelopment is that necessary first step in problem solution and it involves defining the problem, measuring its impact, and searching for i solutions. The primary mission of the Health Effects Research Laboratory in Cincinnati (HERL) is to provide a sound health affects data base in support of j the regulatory activities of the EPA. To this end, IERL conc'ucts a research p-cogram to identify. characterize, and quantitate harmful effects of pollutants tha+, may result from exposure to chemical, physical, or biological agents found in the environment. In addition to the v;lluablc health information generated by these activities, new research techniques and aethods are being developed that contribute to a better uiiderstanLlng of human biochemical and physiologi- cal functions, and how these functio:is are altered by low-level insults. I 1 This report proviilcs an asscsqment of the present environrncntal exposurc i to molybdcnuln and thc Iicalth effccts of such exposure. A guideline for maxi- muin concentration in drinking w:iter i R. J. Garner Director Health Effects Research L;rboratory i . _... -- ABSTRACT . .. Molybdenum is a trace element whicii occurs widely in nature and plays an important role in industrial society. The primary industrial use of nolybde- nun is as an alloy in steels. Major releases to the environment have been associated with several industries including molybdcnum mining and milling, uranium minina and milling, and oil refining. ._ Molybdenun. also plays an important biological role as a micronutrient for plarits and animals. At :ngh levels it can be toxic to animals. While concen- trations in surface waters are generally less than 5 VgMo/L, concentrations as high as 500 pgMo/L have been reported in some drinking waters. Concentra- tions in water greater than 20 ;rgMo/L are almost certainly anthropogenic. ConveGtional wastewater and water treatment technologies are ineffective in the removal of molybdenum. The average human intake via food for the Ui!ited States is 170 iigMo/day while the average intake via drinking water is less than 5 pgMo./day. While no adverse healtt effects have been reported in the Unite6 States, there are reports in the Russian and Tndinn literature of both biochemical and clinical effects in humans at intakes ranging from 1 to 10 mqFlo/day. Rnpid urinary excretion appears to provide considerable protection at inzakes less than 1 mgMo/day. This report reviews the data on rnolyhdenum as it relatrs to the effects of its occurrence iil drinking water. The report also reviews the results of an interdisciplinary study carried out by the authors. The authors recommend a guideline of 50 pg;lo/L for the maximum concentration in drinking water. This report was submitted in fulfillment of Grant No. R-SO3645 by the Environmental Trace Substances Research Program, University of Colorado under the sponsorship of the I1.S. Environmental Frotection Agency. This report covers the period Erom April 7, 1975 to September 30, 1978, and work was completed as of September 30. 1978. 1 .. Cok'respondence should he addressed to: R. .. Willard Chappell i . Director, Cnvirorunental Trace Substances Research Proqram . : Campus Box 215 University cf Colorado Bouider, Colorado 60309 ..... ...! CONTENTS p . 1 .. ................... ............ .. Fo&',iord ;. ............................ .,. .iii. 1 astract ............................................................. iv i. Figures ............................................................ vii 2 : Tables ..... ......................................................... iX 'Acknow1edqmen:s ......................................................... xi .. 1:: Introduction ................................LI...................1 .. Cment on Concentration Units ............................. 2 2 . Conclusions and Recommendations 3 Conclusions ................................................................................ 3. Recommendations ..............................................4 3 ... Chemical properties ............................................ 6 General Chemistry ........................................... 6 .. Bioinorganic Chemistry ........................................ 7 4 .. Measurement Tachnic;ue:; ....................................... 10 SappLing ................................................... 10 Analyses ......L ........................................... 12 Colorimetric Methods .................................... 12 ... P:to!nic i\bsorption Spectrophotometry .....................13 Other Xethri;?:; ............................................. 13 5 . production and .....................................................IIst? production 15 .. Industrial Use 'of Elolybdenum and Its Conpollndo ............ 17 6 . Environmental Fate ........................................... 19 Rocks and Soils ............................................. 19 AirIndustrial ......................................................... Exposure - ?-;:iinq and Milling ................ 20 Indust-rial 'Exposure - . ;h:i.Lting ......................... 22 water ...................................................... 24 .. plarlts ..................................................... 27 f ~ood....................................................... 28 Industrial Souryes . i .......................................
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  • Unicellular Cyanobacteria Exhibit Light-Driven, Oxygen-Tolerant

    Unicellular Cyanobacteria Exhibit Light-Driven, Oxygen-Tolerant

    bioRxiv preprint doi: https://doi.org/10.1101/619353; this version posted May 2, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. 1 Unicellular Cyanobacteria Exhibit Light-Driven, Oxygen-Tolerant, 2 Constitutive Nitrogenase Activity Under Continuous Illumination 3 James Young, Liping Gu, Michael Hildreth, Ruanbao Zhou 4 Department of Biology and Microbiology, South Dakota State University, Brookings, SD 5 6 7 8 9 10 11 12 13 14 15 16 17 18 bioRxiv preprint doi: https://doi.org/10.1101/619353; this version posted May 2, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. 19 Abstract 20 Cyanobacteria have played a profound role in shaping the biosphere, most notably 21 through the Great Oxygenation Event (GOE) with the advent of photosynthesis1. Cyanobacteria 22 also contribute to global primary production through biological nitrogen fixation (BNF) using 23 nitrogenase2,3, an oxygen-labile enzyme complex that evolutionarily predates the GOE4. Current 24 literature reports nitrogenase activity in unicellular cyanobacteria is protected from oxygen 25 through diurnal separation of photosynthesis and BNF5. However, historic conditions of 26 continuous-light and warm temperature at polar latitudes during the Triassic and Cretaceous may 27 have created a selective advantage amongst unicellular cyanobacteria for non-temporal 28 mechanisms of maintaining nitrogenase activity in the presence of oxygen. Here we report 29 constitutive nitrogenase activity concurrent with a net-gain of oxygen through photosynthesis in 30 a continuous-light adapted culture of the unicellular cyanobacteria, Cyanothece sp.