Parliamentary Questions

5 Mar 2004: Column 1143W

Mr. Paterson: To ask the Secretary of State for Environment, Food and Rural Affairs pursuant to the answer of 11 February 2004, Official Report, column 1441W, on bovine TB, what criteria were used to assess the humaneness of the pesticide fumigants approved for the destruction of rabbits and moles. [158427]

Alun Michael: The Control of Pesticides Regulations 1986 (COPR) requires pesticides to be humane and this issue in relation to approved vertebrate control agents was considered by the Advisory Committee on Pesticides in 1996.

Quantification of "humaneness" was attempted using the assumptions

(a) that the extent to which a fumigant is humane is universally related to the degree of distress,
(b) that increased severity of symptoms indicates the degree of distress caused, and
(c) that increased duration of symptoms increased distress. Since effects resulting in the death of an intoxicated animal will probably involve severe symptoms at least in extremis, the duration of severe symptomatology is used as a major determinant in assessment of humaneness. For judging the severity of symptoms reported among the following data listed, the criteria described in "Pain and Distress in Laboratory

5 Mar 2004: Column 1144W

Rodents and Lagomorphs: Report of the Federation of Laboratory Animal Science Associations Working Group on Pain and Distress" have been used as a guide.

The Working Group on Methods for Assessing the Humaneness of Vertebrate Pesticides concluded that pain, distress and suffering could not be measured objectively but that a subjective assessment of humaneness was possible, based on physiological and behavioural data, knowledge of mode of action and post-mortem reports.

The Littlewood report (1965) recommended that procedures (or in this case conditions) which are known to cause pain in humans should be assumed to do so in other vertebrates unless convincing evidence is available to the contrary.

5 Mar 2004: Column 1144W

Mr. Paterson: To ask the Secretary of State for Environment, Food and Rural Affairs how many incidents of disease in humans have been attributed to TB infection in cats. [158006]

Miss Melanie Johnson: I have been asked to reply.
There have been no reported cases of tuberculosis infection in humans attributed to infection in cats.

5 Mar 2004: Column 1147W

Mr. Paterson: To ask the Secretary of State for Environment, Food and Rural Affairs what the mode of action of (a) aluminium phosphide and (b) hydrogen cyanide is in terms of its effects on small mammals when used as a pesticide. [157930]

Alun Michael: The following modes of action apply to all mammals, not just small ones.

(a) Phosphine:
The primary mode of toxic action of phosphine is considered to be inhibition of cytochrome oxidase in the respiratory metabolism pathway, with additional direct cytotoxicity. Exposure to high concentrations of phosphine leads in vertebrates to a profound fall in blood pressure, followed by death. Lower concentrations cause pulmonary oedema and respiratory failure which may be fatal.

(b) Hydrogen Cyanide:
Cyanide combines with the ferric iron atom in haem proteins (eg cytochromes) in vertebrate tissues, impairing their capacity to undergo oxidation and reduction in the normal electron transport process. It can cause death extremely rapidly, primarily by inactivating cytochrome oxidase in tissues.