Number 43 October 1994
MAFF UK - DIOXINS IN COWS' MILK
Index to MAFF, UK Food Surveillance Information
Sheets, 1994
see also:
19: MAFF, UK
- Dioxins in Cows Milk (November 1993)
44:
MAFF, UK - Contaminants in Cow's Milk from the Clitheroe Area (October 1994)
75: MAFF, UK - Dioxins in Cows Milk from
the Bolsover Area (November 1995)
100: MAFF, UK - Dioxins in Cows Milk from
Farms Close to Industrial Sites (January 1997)
107: MAFF, UK - Dioxins and PCBs
in Cows Milk from Farms Close to Industrial Sites (June 1997)
120: MAFF UK - Dioxins in Cows' Milk from
Northern Ireland (August 1997)
123:
MAFF, UK - Dioxins and PCBs in Cows Milk from Farms Close to Industrial Sites:
1996 Survey Results (August 1997)
124: MAFF UK - Dioxins in Cows Milk from
the Bolsover Area (August 1997)
133:
MAFF, UK- Dioxins and PCBs in Cows' Milk from farms close to Industrial Sites:
Rotherham 1997 (November 1997)
134:
MAFF, UK- Dioxins and PCBs in Cows' Milk from the Bolsover Area - October 1997
(November 1997)
135: MAFF, UK-
Dioxins and PCBs in Cows' Milk from farms close to Industrial Sites:
Huddersfield 1997 (November 1997)
136: MAFF, UK- Dioxins and PCBs in Retail
Cows' Milk in England (December 1997)
143: MAFF UK - Dioxins and PCBs in Cows'
Milk from the Bolsover Area Collected in October and November 1997 (March 1998)
145: MAFF UK - Dioxins and PCBs in Farmed
Trout in England and Wales (March 1998)
184: MAFF UK - Dioxins and PCBs in UK and
Imported Marine Fish (August 1999)
Background
'Dioxins' is the generic term given to polychlorinated dibenzo-p-dioxins
and dibenzofurans. Concern over dioxins arose initially because one particular
dioxin, 2,3,7,8-TCDD, was found to produce clinical effects (chloracne) in
workers exposed to it through industrial accidents. It is also toxic to some
species of laboratory animals. The other dioxins are less toxic and
concentrations of those compounds are multiplied by a weighting factor
reflecting their relative toxicities to give a total dioxins content in terms of
'Toxic Equivalents' (TEQs). Dioxins are produced during various combustion
processes and are also unwanted by-products in the manufacture of certain
chlorinated compounds. As a result, dioxins are ubiquitous environmental
contaminants and are generally present in very low concentrations in all foods
including cows' milk. Past surveillance has shown that the normal expected
range of dioxins concentrations in cows' milk from farms close to
urban/industrial areas is 0.12 - 0.27 ng TEQ/kg (1 ng/kg is one part per
trillion).
Previous surveillance results for dioxins were summarised in the January
1993 and November 1993 issues of the Food Safety Information Bulletin (Numbers
33 and 43). These results showed elevated concentrations of dioxins in cows'
milk from three farms (Farms A, B and C) in the Bolsover area of Derbyshire,
although concentrations had fallen steadily during the period October 1990 to
September 1993. Further samples of milk were taken from five farms in the area,
including Farms A and B, in July 1994. Samples were not taken from Farm C owing
to practical difficulties in obtaining samples from the cows on that farm.
However, dioxin concentrations in milk from Farm C were well within acceptable
limits when previously sampled and analysed.
Results
Samples from Farms F, G and H were taken from the bulk milk tanks on these
farms. Samples from Farms A and B were taken from individual cows as these
farms run suckler herds and do not currently produce milk for human consumption.
All samples were analysed by gas chromatography-mass spectrometry at the CSL
Food Science Laboratory, Norwich.
As in September 1993, the concentrations of dioxins found (see
Table 1) for all samples except those from Farm B were
within the expected range for farms close to urban/industrial areas. The
concentrations of milk from Farm B continue to exceed the expected range. These
findings are not unexpected as dioxins are very long-lived in the environment.
Interpretation
With the exception of Farm B, the concentrations of dioxins found in the
milk are well below the Maximum Tolerable Concentration of 0.7 ng TEQ/kg set by
MAFF and the Department of Health. Farm B does not produce milk for human
consumption and there is therefore no direct risk to human health from the milk.
Contact point
For further information, please contact:
Dr Nigel Harrison
MAFF, Food Safety and Science Group
Food
Contaminants Division
Room 234 Ergon House, c/o Nobel House
17 Smith
Square
London SW1P 3JR
Tel: + 44 (0) 171 238 6235
Fax: + 44
(0) 171 238 5331
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