Showing papers on "Trace metal published in 1972"

Enrichment of Heavy Metals and Organic Compounds in the Surface Microlayer of Narragansett Bay, Rhode Island

Abstract: Concentrations of lead, iron, nickel, copper, fatty acids, hydrocarbons, and chlorinated hydrocarbons are enriched from 1.5 to 50 times in the top 100 to 150 micrometers of Narragansett Bay water relative to the bulk water 20 centimeters below the surface. Trace metal enrichment was observed in the particulate and organic fractions but not in the inorganic fraction. If these substances are concentrated in films only a few molecular layers thick on the water surface, the actual enrichment factor in the films may be well over 10(4), resulting in extremely high localized pollutant concentrations in the surface microlayer.

Trace metal enrichment in the sea‐surface microlayer

Abstract: Sea-surface microlayer samples have been analyzed for the trace metals aluminum, copper, iron, manganese, nickel, lead, and vanadium by atomic absorption and neutron activation. Samples were collected with polyethylene screens in the estuarine waters of Narragansett Bay, Rhode Island, the coastal waters of the New York Bight, and open ocean regions between Iceland and Nova Scotia. Metal enrichment in the ‘particulate’ and ‘chloroform-extractable’ fraction of the surface microlayer compared to water 20 cm below the surface varied from virtually none up to approximately 50 for copper, iron, and nickel and up to 20 for lead in the Narragansett Bay samples. There was no enrichment in the soluble, ‘inorganic’ fraction of the surface microlayer for those metals in Narragansett Bay. The degree of surface enrichment was correlated with the presence of observable slicks on the water surface. None of the New York Bight or open ocean samples were collected while observable slicks were present. Significant enrichments in particulate and chloroform-extractable phases in the surface microlayer still occurred in the majority of cases in both areas. The variability of its occurrence and magnitude may be due to several factors, including the presence of coherent slicks, biological activity, and local pollution sources, both atmospheric and water. On the open ocean, atmospheric input of some trace metals to the surface microlayer may be quite significant. Where surface microlayer enrichment of trace metals does occur, enrichment of these metals on sea-salt aerosols formed at the sea surface may also occur.

The assessment of individual variability to trace metal insult: low-molecular-weight metal complexing agents as indicators of trace metal insult.

Abstract: The interaction and time distribution of cadmium, lead, and copper in the sera and red blood cells of rats dosed repeatedly with subacute amounts of cadmium have been studied by using the combined techniques of anodic stripping voltammetry and gel filtration chromatography. Low-molecular-weight trace metal complexing agents in the serum were identified. Their significance as possible indicators of individual variation in response to heavy metal insult and as a means of assessing environmental levels is discussed.

Trace metal contents, chemical properties and oxidative stability of capelin and herring oils produced in norwegian plants

Abstract: The iron and copper contents of 14 crude capelin oils, two herring oils and one blend produced in oil meal plants in northern Norway were determined by atomic absorption spectroscopy (AAS). Their oxidative stability, peroxide (PV), benzidine (BV) and iodine values (IV), free fatty acids (FFA) and tocopherol contents were also evaluated. The oxidative stability was found to be more dependent on the tocopherol content and BV of the crude oils than on their content of trace metals. Changes in iron, copper and nickel contents were determined by AAS after refining and hydrogenation of marine oils in two Norwegian hydrogenation plants. The content of trace metals in the oils and hydrogenated products decreased as a result of alkali refining and bleaching to the lower limits of detectability by the method used, and amounted to 0.01 (oils), 0.02 and <0.3 ppm for iron, copper and nickel respectively.

Trace elements in soil and plants and antral cancer.

Abstract: The trace metal content of plant material used for snuff was found to be closely related to the soil content. The contamination of preparations does not seem to be a factor. Not all snuff users get cancer of the maxillary antrum. It may be that people using plant material for snuff from certain soils high in nickel and chromium would be a high-risk population.

Trace metal distributions in natural salt marsh sediments

Abstract: t h e r e q u i r e m e n t s f o r a n a d v a n c e d d e g r e e f r o m t h e G e o r g i a I n s t i t u t e o f T e c h n o l o g y , I a g r e e t h a t t h e L i b r a r y o f t h e I n s t i t u t e s h a l l m a k e i t a v a i l a b l e f o r i n s p e c t i o n a n d c i r c u l a t i o n i n a c c o r d a n c e w i t h i t s r e g u l a t i o n s g o v e r n i n g m a t e r i a l s o f t h i s t y p e . I a g r e e t h a t p e r m i s s i o n t o c o p y f r o m , o r t o p u b l i s h f r o m , t h i s d i s s e r t a t i o n m a y b e g r a n t e d b y t h e p r o f e s s o r u n d e r w h o s e d i r e c t i o n i t w a s w r i t t e n , o r , i n h i s a b s e n c e , b y t h e D e a n o f t h e G r a d u a t e D i v i s i o n w h e n s u c h c o p y i n g o r p u b l i c a t i o n i s s o l e l y f o r s c h o l a r l y p u r p o s e s a n d d o e s n o t i n v o l v e p o t e n t i a l f i n a n c i a l g a i n . I t i s u n d e r ­ s t o o d t h a t a n y c o p y i n g f r o m , o r p u b l i c a t i o n o f , t h i s d i s ­ s e r t a t i o n w h i c h i n v o l v e s p o t e n t i a l f i n a n c i a l g a i n w i l l n o t b e a l l o w e d w i t h o u t w r i t t e n p e r m i s s i o n .