But I hope Mr Dyson is right when he says that he thinks all the fashionable paranoia about pollution is a bit of an exaggerated scare. Rivers are just too important to us to be able to take the risk. Men have always settled on rivers because they are a vital aspect of man's natural environment; they provide a possible means of transportation, a natural recreation ground, and an essential environment for the wildlife that helps to support man, as well as being a built-in water supply and a natural sewage system.

That is one side of it - man is part of a total system that has grown up to be a complete cycle of mutual support. (That's what society is meant to be too!)

But man is unique in being able and all too short-sightedly willing to mess around his environment, and everything else's: all animals can adapt to their changing circumstances, but only man can adapt his environment to himself too.

That is what pollution is: for the adaptations of the environment that we have brought about have been rarely - and then only accidentally - beneficial in the long term to us and to the rest of nature.

Recently it has become admirably fashionable to bitch about ecology, but it is easier to do damage than to undo it. How do we try and repair the world and still be sure that we're not causing more damage? We spend a lot of time and money putting right one mess only to find it messes up something else that we hadn't realised was connected. The whole of life on earth is too intimately (and delicately) interconnected for us to be sure that anything we do won't have undesirable side-effects. That's why the big scare.

Since the first man ever lit his first fire we have been impinging on the world around us, and the accelerated pace of city growth and the Industrial Revolution have succeeded faster and faster in taking over our environment with biologically undesirable results.

As a natural part of the system the rivers and seas can provide us with an extremely large but finite amount of fresh unpolluted water and sewerage facilities.

But you can push the natural processes too far, and this is what has been done to the rivers of the north-east. It takes just a short time to kill everything in a river, but it takes decades of dedicated application to restore a natural balance and a healthy river. Both the Tyne and the Tees have "achieved international notoriety" as examples of gross estuarial pollution; the Tees is "probably the most polluted river in the country" - 3 times worse than the Tyne. And some people still do not see why there is such a scare on.

So a certain amount is being done. The River Authorities do a pretty good job, but their legal position is limited. While they can supervise all the discharges into - and so the quality of - rivers in non-tidal stretches, they have no control over any discharges that were started before 1960 into the estuaries. And that is most of what has made the Tyne and the Tees "grossly polluted". But then, nearly everyone is pretty keen to get that changed.

The problem is time. It's not only the rivers that are getting worse, but the whole pattern of which they are an intrinsic part. We just can't afford loopholes like that - literally on pain of death.

There is a Royal Commission on environmental pollution that has some interesting things to say about the state of our world: "Nothing less than a comprehensive policy for the whole environment will suffice". Yeah, so let's go!

But getting nearer to the practical meat of the matter: "Economic and technological achievements over the last generation have been considerable: they have brought immense and worthwhile benefits to millions of people. But the benefits have been at the cost of a deterioration in our physical environment... Society has become aware that economic output is not an end in itself. It is only a means to promote human welfare. Unless appropriate policies are adopted, some forms of output can be pushed beyond the point where they make a net contribution to human welfare".

Right on! but if that's so, we've got to get away from evasive action about economics and cost-effectiveness. The Commission in a roundabout way make the point that there is no objective sense of responsibility among private polluters, or public authorities, due to the present institutional structure of society.

Responsibility lies with you, and me, and them. It's about time everyone started feeling the necessary urgency: time is not on our side, and we are not yet sufficiently enlightened in our actions. We must all do our bit (but some people's bits are bigger than others!).

So often nothing is done because of the unwillingness of those responsible, not because of lack of technical knowledge or inadequate legislation.

We must balance economics and technology against ecology - and start coming out with wiser answers. See it as gadgets, and advertising, and speed, and flashiness as against green grass, and trees, and kingfishers and salmon, if you like. But make sure you realise you've got to choose.

Beauty lies in ecological repose. Love the beauty of the world, but first make sure it's beautiful.

Maurice

Pollution in rivers takes three basic forms:

1. toxic - mainly arising from metal, coking, chemical and tar industries. Many poisons are harmful in concentrations as low as 1:1,000,000 parts.
2. suspended solids - arising mainly from collieries and sand and gravel plants - cause turbidity, affecting the life in the rivers by laying down silt on the river bed and cutting out the light.
3. organic matter - the main and most aesthetically offensive pollutant of this type is sewage, which is still largely discharged untreated into the rivers, "a revolting and uncivilised practice". Organic matter absorbs dissolved oxygen in the water; this oxygen is held in solution to a saturation level of 10:1,000,000 parts of water. If it falls below 70% saturation, most fish will die.

The rivers of the north-east were once famous for salmon. The Tyne estuary does not allow the passage of these migratory fish, except at times of maximum flow when there is a layer of cleaner water on the surface that the fish can pass through. The whole tidal stretch of the river is grossly polluted by crude sewage. The Wear too suffers from crude sewage, but not so severely, because the sewage outlets are so near the sea. Both these rivers and their tributaries are more or less polluted over a large proportion of their length.

The Tees has a different problem. Most of its pollution is from toxic industrial waste. The last 19 miles of the estuary are often completely denuded of dissolved oxygen.

The smaller rivers of Northumbria are in general of a better quality, and not deteriorating or are even improving. The Tweed and its tributaries are all clean, except the Breamish. The Tweed estuary would be more polluted if the discharges of crude sewage into it were not so near the sea.

And then, of course, all the rivers and their pollutants pour into the North Sea. There are already local effects on the marine life along the Durham coast. But that is another matter ... or is it?