Diphosphoric acid, copper salt

Bioaccumulation: terrestrial

Link to relevant study record(s)

Reference

Endpoint:

bioaccumulation: terrestrial

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
For further information please refer to read across justification in IUCLID section 13.

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read-across source

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Remarks on result:

other: By using a weight of evidence approach it is demonstrated that copper is well regulated in all living organisms and that BCF and BAF values have no meaning for a hazard assessment.

Key result

Remarks on result:

other: By using a weight of evidence approach it is demonstrated that copper is well regulated in all living organisms and that BCF and BAF values have no meaning for a hazard assessment.

Key result

Remarks on result:

other: By using a weight of evidence approach it is demonstrated that copper is well regulated in all living organisms and that BCF and BAF values have no meaning for a hazard assessment.

Validity criteria fulfilled:

not applicable

Conclusions:

By using a weight of evidence approach it is demonstrated that copper is well regulated in all living organisms and that BCF and BAF values have no meaning for a hazard assessment.

Executive summary:

By using a weight of evidence approach it is demonstrated that copper is well regulated in all living organisms and that BCF and BAF values have no meaning for a hazard assessment.

Almost regardless of the degree of environmental contamination, the retention of copper in mammalian systems is regulated by absorption-excretion equilibria that adapt to maintain a homeostatic situation. However, accumulation of copper does occur in some groups of terrestrial invertebrates in relation to dietary concentrations of the metal.

Description of key information

For the purposes of assessing the bioaccumulation hazard of copper (II) pyrophosphate, the phosphate moiety is not considered to be bioaccumulated and therefore the chemical species of interest is copper. There is a considerable amount of copper accumulation data available. The data demonstrate an inverse relation between the copper bioaccumulation from soil and the copper concentrations in the soil. The information demonstrates that copper is well regulated in all living organisms and that the BCF and BAF values have no meaning for a hazard assessment. The data also demonstrate that copper is not biomagnified in the terrestrial ecosystems and that there is no issue for secondary poisoning of copper.

Additional information

1. Terrestrial BCF and BAF

As for the aquatic environment, homeostatic regulation of copper (and other metals) is also relevant to soil organisms.

An inverse relationship between copper soil BCF (concentrations in plants/ concentrations in soils) and copper concentrations in the soils wwas observed by

-       Abrahams and Thornton (1994) for pasture herbage

-       Ginocchio et al (2002) for lettuce, tomato and onions and by Tambasco et al (2000) for lettuce (Lactuca sativa)

An inverse relationship between copper soil BAF (concentrations in invertebrates/ concentrations in soils) and copper concentrations in the soils was observed by:

-       Janssen et al (1997) forEisenia Andrei

-       Heikens et al (2001) for different invertebrate species, collected in the field data

-       Svendsen and Weeks (1997) forLumbricus sp.

-       Sample et al. (1999), who developed a database of Cu concentrations in soil and earthworm tissue.

-       Wong and Cheung (1986) demonstrated that caterpillars of the white butterfly (Pieris conidia) ingesting large amounts of plant leaf material, do not concentrate metals. Lower Cu contents are found in the organism than in the plant material (BCF of 0.1 to 0.3).

This section further includes some supporting data of relevance to secondary poisoning:

- Chaney et al, 1983 introduced the term “Soil-Plant Barrier” for describing the mechanisms behind reduced plant uptake. A “Soil-Plant Barrier” protects the food chain from toxicity of a microelement when one or more of abiotic or biotic processes limit maximum levels of that element in edible plant tissues to levels safe for animals: 1) insolubility of the element in soil prevents uptake; 2) immobility of an element in fibrous roots prevents translocation to edible plant tissues; or 3) phytotoxicity of the element occurs at concentrations of the element in edible plant tissues below that injurious to animals. 

-       Smit et al (2000) assessed the secondary poisoning for copper and calculated an average BAF of 0.09 for earthworms based on an extensive Dutch database (170 data points) – they concluded that for copper it was not necessary to integrate secondary poisoning aspects into the copper aquatic quality criteria.

2. Bio-magnification factor (BMF)

Lakowski (1991) explored the pattern of bio-magnification of Cu in the terrestrial invertebrate’s food web. Based on 37 bio-magnification factors representing herbivores, carnivores and detrivores, the slope of the linear regression was less than 1 suggesting regulation of Cu concentration.

Hunter and Johnson (1982) examined the food chain transfer of Cu and Cd in contaminated grassland around a refinery. Metal movement between producers, herbivores and carnivore trophic levels was examined with an emphasis on the small mammal components of the food web. Animal: diet ratios decreased with increasing soil concentrations and were all smaller than 0.2. This illustrates the degree of homeostatic regulation exercised by mammalian systems over body tissue retention of ingested Cu.

On the basis of a literature review, Heikens et al (2001) compared Cu accumulation between different invertebrate species. Metal body concentrations were highest in Isopoda and lowest in Coleoptera. Differences in metal accumulation between taxonomic groups were ascribed to differences in metal kinetics, regulation mechanism and the exposure route. Terrestrial Isopoda are detrivores who live on litter and feed on organic matter. On the other hand Coleoptera are either herbivores or carnivores and have less intensive contact with litter.   

Wittassek (1987) came to a similar conclusion when studying the uptake of Cu in vineyard soil organisms adapted to 60 years of continuous use of Cu sulphate fungicides. Slugs, Isopods and Diplopods (detrivores) showed the highest accumulation of Cu. Chilopoda and spiders, as predators, had high Cu concentrations only when their prey concentrations were high (they did not bioaccumulate).

The data demonstrate an inverse relation between the copper bioaccumulation from soil and the copper concentrations in the soil. The information demonstrates that copper is well regulated in all living organisms and that the BCF and BAF values have no meaning for a hazard assessment. The data also demonstrate that copper is not biomagnified in the terrestrial ecosystems and that there is no issue for secondary poisoning of copper.