It seems to me another point is missing:

Even if the PCB levels were 10 fold over background does this have any
effect on toxicity or palatability? 10 times next to nothing (especially
if it is not significant) may amount to not much and still way below any
sensible limit. Anyway PCB s are long term toxins so infrequent small
excursions outside MRLs are unlikely to matter - Andy Renwick and Ron
Walker wrote something about excursions over the ADI and their likely
(lack of) effect. Progression through several further steps and
conservative defaults to obtain a maximum residue level is likely to
result in a very conservative value of little or no use in risk
assessment. The whole thing is likely to be yet another triumph of
journalism in driving public perception of risk (perceived risk) way out
of alignment with technical (actual, expert judgement based) assessed
risk. Such is the sociological unacceptability of the psychological
paradigm of risk assessment! This episode illustrates the need for
stakeholder involvement (see the recent US Presidential Congressional
Commission on Risk Assessment and Risk Management report) and the power
of the press to propogate and distort messages (vide Kasperson et al,
1988, Risk Analysis) !


Paul Illing

8 Jan 01

In message <[log in to unmask]>, Gary Greenberg
<[log in to unmask]> writes
>UK salmon farmers hit back at toxin allegations
>
>Whole text at original website:
>http://www.planetark.org/dailynewsstory.cfm?newsid=9447
>
>UK: January 5, 2001
>
>EDINBURGH - Scotland's salmon farmers hit back on Thursday at
>allegations that farmed fish could contain dangerous levels of toxins.
>
>A BBC documentary to be broadcast on Sunday will say that the 'King of
>Fish' grown in artificial cages can contain as much as 10 times the
>levels of certain pollutants - polychlorinated biphenyls (PCBs) and
>dioxins - than are found in their wild counterparts.
>
>PCBs are thought to attack the central nervous system, causing learning
>difficulties and suppressing the body's natural immune system, says the
>programme, a transcript of which has been obtained by Reuters.
>
>"We are outraged that the BBC has sought to promote a health scare story
>to promote one of its own programmes," said a spokeswoman for Scottish
>Quality Salmon, which represents 70 percent of the UK industry.
>
>...
>
>Shares in Dutch food group Nutreco , the world's biggest salmon farmer,
>fell 6.5 percent by 1400 GMT on fears the documentary would damage
>public confidence in the fish.
>
>The documentary, called 'Warnings from the Wild - the Price of Salmon' -
>includes research from Michael Easton of Canada's Suzuki Foundation who
>analysed four different types of fish feed alongside four different
>farmed and wild salmon.
>
>...
>
>In an echo of Britain's mad cow disease, Easton said the feeding of high
>protein meal made from fish caught far out at sea could be the reason
>for the concentration of the toxins in the farmed salmon.
>
>BRITAIN SAYS SALMON SAFE
>
>Britain's Food Standards Agency (FSA), set up in the wake of the mad cow
>crisis, stuck to its guns and insisted one portion of farmed salmon per
>week was fine for the average adult.
>
>In a statement, the FSA said eating moderate amounts of oily fish,
>including salmon, was part of a healthy, balanced diet and outweighed
>any individual risk.
>
>The FSA is at odds with the World Health Organisation which has lowered
>its recommended weekly intake of dioxins and PCBs in light of new
>findings, according to the documentary.
>
>Salmon farming in Scotland has grown from virtually nothing over the
>last 20 years into a 300-million-pound industry employing around 6,500
>people.
>
>Around 95 percent of salmon on Britain's dinner plates comes from the
>huge metal cages dotted around the mouths of sea lochs on the west
>coast.
>
>Salmon remains a hugely popular dish, especially during the festive
>season, although public faith in the farmed variety has been knocked by
>infestations of sea lice caused by having large numbers of fish packed
>into cages, almost like battery chickens.
>
>Story by Ed Cropley
>
>REUTERS NEWS SERVICE
>
>
>
>--
>Gary N. Greenberg, MD MPH    Sysop / Moderator Occ-Env-Med-L MailList
>[log in to unmask]     Duke Occupat, Environ, Int & Fam Medicine
>OEM-L Maillist Website:                      http://occhealthnews.com

--
Paul Illing