Calculated loading rates of trace metals into the three environmental compartments demonstrate that human activities now have major impacts on the global and regional cycles of most of the trace elements. There is significant contamination of freshwater resources and an accelerating accumulation of toxic metals in the human food chain.

Quantitative assessment of worldwide contamination of air, water and soils by trace metals

https://digital.library.unt.edu/ark:/67531/metadc888955/m2/1/high_res_d/900147.pdf

ENDF/B-VII.0: Next Generation Evaluated Nuclear Data Library for Nuclear Science and Technology

A compilation of charged-particle induced thermonuclear reaction rates

A PROPER inventory of atmospheric emissions from natural sources is basic to our understanding of the atmospheric cycle of the trace metals (and metalloids), and is also needed for assessing the extent of regional and global pollution by toxic metals1. It is generally presumed that the principal natural sources of trace metals in the atmosphere are wind-borne soil particles, volcanoes, seasalt spray and wild forest fires2–6. Recent studies have shown, however, that particulate organic matter is the dominant component of atmospheric aerosols in non-urban areas7–10 and that over 60% of the airborne trace metals in forested regions can be attributed to aerosols of biogenic origin11,12. Here I estimate that biogenic sources can account for 30–50% of the global baseline emissions of trace metals. For most of the toxic metals, the natural fluxes are small compared with emissions from industrial activities, implying that mankind has become the key agent in the global atmospheric cycle of trace metals and metalloids.

A global assessment of natural sources of atmospheric trace metals

A global assessment of naturalsources of atmospheric trace metals

Session I: Metalloids and the Hydride Generation.- The Determination of the Chemical Species of Some of the "Hydride Elements" (Arsenic, Antimony, Tin, and Germanium) in Sea Water: Methodology and Results.- Antimony Content and Speciation in the Water Column and Interstitial Waters of Saanich Inlet.- Ultratrace Speciation and Biogenesis of Methyltin Transport Species in Estuarine Waters.- The Relationship of the Distribution of Dissolved Selenium IV and VI in Three Oceans to Physical and Biological Processes.- Session II: Arctic Chemistry.- Trace Metals in the Arctic Ocean.- Copper in Sub-Arctic Waters of the Pacific Northwest.- Low Level Determination of Trace Metals in Arctic Sea Water and Snow by Differential Pulse Anodic Stripping Voltammetry.- The Relationship between Distributions of Dissolved Cadmium, Iron, and Aluminium and Hydrography in the Central Arctic Ocean.- Session III: Intercalibration Exercise.- Intercomparison of Seawater Sampling Devices for Trace Metals.- The Analysis of Trace Metals in Biological Reference Materials: A Discussion of the Results of the Intercomparison Studies Conducted by the International Council for the Exploration of the Sea.- An Intercomparison of Sampling Devices and Analytical Techniques Using Sea Water from a CEPEX Enclosure.- Session IV: Estuarine Processes Involving Metals.- Role of Fresh Water/Sea Water Mixing on Trace Metal Adsorption Phenomena.- Effects of Particle Size and Density on the Transport of Metals to the Oceans.- The Effect of Sewage Effluents on the Flocculation of Major and Trace Elements in a Stratified Estuary.- Impoverishment and Decrease of Metallic Elements Associated with Suspended Matter in the Gironde Estuary.- The Significance of the River Input of Chemical Elements to the Ocean.- Session V: Air/Sea Exchange and Coastal Processes Involving Metals.- Air-Sea Exchange of Mercury.- Separation of Copper and Nickel by Low Temperature Processes.- The Fate of Particles and Particle-Reactive Trace Metals in Coastal Waters: Radioisotope Studies in Microcosms.- Trace Metals in a Landlocked Intermittently Anoxic Basin.- Session VI: Ocean Distribution and Analysis.- Thorium Isotope Distributions in the Eastern Equatorial Pacific.- Aspects of the Surface Distributions of Copper, Nickel, Cadmium, and Lead in the North Atlantic and North Pacific.- Mn, Ni, Cu, Zn, and Cd in the Western North Atlantic.- Some Recent Measurements of Trace Metals in Atlantic Ocean Waters.- Determination of the Rare Earth Elements in Sea Water.- The Cycle of Living and Dead Particulate Organic Matter in the Pelagic Environment in Relation to Trace Metals.- Trace Metal Levels in Sea Water from the Skagerrak and the Kattegat.- Mercury Concentrations in the North Atlantic in Relation to Cadmium, Aluminium and Oceanographic Parameters.- Perturbations of the Natural Lead Depth Profile in the Sargasso Sea by Industrial Lead.- Copper, Nickel and Cadmium in the Surface Waters of the Mediterranean.- Accurate and Precise Analysis of Trace Levels of Cu, Cd, Pb, Zn, Fe and Ni in Sea Water by Isotope Dilution Mass Spectrometry.- Session VII: Chemical Speciation.- Studies of the Chemical Forms of Trace Elements in Sea Water Using Radiotracers.- Trace Metals (Fe, Cu, Zn, Cd) in Anoxic Environments.- The Behavior of Trace Metals in Marine Anoxic Waters: Solubilities at the Oxygen-Hydrogen Sulfide Interface.- Variations of Dissolved Organic Copper in Marine Waters.- Trace Metals Speciation in Nearshore Anoxic and Suboxic Pore Waters.- The Contrasting Geochemistry of Manganese and Chromium in the Eastern Tropical Pacific Ocean.- Potentialities and Applications of Voltammetry in Chemical Speciation of Trace Metals in the Sea.- Studies of Cadmium, Copper and Zinc Interactions with Marine Fulvic and Humic Materials in Seawater Using Anodic Stripping Voltammetry.- Chemical Periodicity and the Speciation and Cycling of the Elements.- Potentiometric and Conformational Studies of the Acid-Base Properties of Fulvic Acid from Natural Waters.- Copper Speciation in Marine Waters.- Session VIII: Metals and the Biosphere.- Plankton Compositions and Trace Element Fluxes from the Surface Ocean.- Metals in Seawater as Recorded by Mussels.- Trace Elements and Primary Production: Problems, Effects and Solutions.- Trace Metals and Plankton in the Oceans: Facts and Speculations.- Sensitivity of Natural Bacterial Communities to Additions of Copper and to Cupric Ion Activity: A Bioassay of Copper Complexation in Seawater.- List of Participants.- Index of Authors.

Trace Metals in Sea Water

The 14.8-Mev protons from the Livermore variable-energy cyclotron have been used to study ($p, n$) spectra from 13 selected target nuclei with mass numbers from 48 to 93 for a laboratory angle of 23\ifmmode^\circ\else\textdegree\fi{}. Neutron energies were determined using standard time-of-flight techniques. All spectra show one strong neutron group at an energy corresponding in excitation in the final nucleus to the isobaric counterpart (analog state) of the target ground state, i.e., the $Q$ value is the usual Coulomb energy displacement. The strong forward peaking of the angular distribution of the neutrons corresponding to the analog state in ${\mathrm{V}}^{51}(p, n){\mathrm{Cr}}^{51}$ confirms the direct nature of the reaction. Although it is tempting, on the basis of the narrow width of the isobaric states (300 kev), to imply some validity to isotopic spin as a quantum number for masses up to $A=93$, Lane and Soper have shown that isobaric states in adjoining nuclei can occur even in mass regions where isotopic spin is not a good quantum number.

Isobaric States in Nonmirror Nuclei

The agreement of Coulomb displacement energies derived from the nonmirror (p,n) isobaric reaction with those obtained from mirror and nonmirror (T=1) nuclei beta decay has been previously demonstrated. Using the Livermore 90-in. cyclotron time-of-flight facility, we have measured additional Coulomb displacement energies in the mass region 70≤A≤108. These measurements indicate possible shell effects which were previously not observed because of the paucity of data. With the availability of 20.5-MeV protons, Coulomb displacement energy measurements were extended to the mass region A≤165. Even for nuclei as heavy as Ho165, where the Coulomb displacement energy is 16.6 MeV, the width of the isobaric neutron group was not measurable (≤150 keV). The variation of the uniform radius parameter with atomic weight (A) inferred from these data is compared with that obtained from high-energy electron scattering experiments and is found to be in substantial agreement. A semiempirical formula for calculating Coulomb displacement energies is presented.

Coulomb Displacement Energies Derived from the p, n Isobaric Reaction

Using pulsed-beam neutron time-of-flight spectrometry relative differential cross sections for /sup 7/Li(p, n/sub 0/)/sup 7/Be(g.s.) and /sup 7/Li(p, n/sub 1/)/sup 7/Be* (0.431 MeV) have been measured over the laboratory angular range 3.5degree to 159degree and from an incident bombarding energy of 4.2 to 26 MeV. These cross sections have been integrated over angle and at 5 MeV the resulting integral was normalized to the absolute measurement of Macklin and Gibbons in order to obtain absolute differential and total cross sections for each neutron group. At energies above 6 MeV the 3.5degree cross section for each group decreases monotonically, reaching a minimum at about 12 MeV. Both cross sections then increase, the ground-state cross section approaching a center-of-mass value of 15 mb/sr at 26 MeV. The forward-angle ratio of n/sub 1/ to n/sub 0/ neutrons remains around 30% from 8 to 26 MeV, obtaining a maximum of about 35% at 26 MeV. The integrated cross sections, on the other hand, both decrease from 6 MeV to the maximum energy. Neutrons from states in /sup 7/Be at 4.55, 6.51, 7.19, and possibly 10.79 MeV as well as those from three-body breakup were also observed in this experiment. (AIP)

C. Wong

Papers

Trace Metals in Sea Water

Isobaric States in Nonmirror Nuclei

Coulomb Displacement Energies Derived from the p, n Isobaric Reaction

Cross sections for the Li-7 (p, n) Be-7 reaction between 4.2 and 26 MeV

Direct (p,n) Reaction in Medium A Nuclei: A Configuration-Selective Process