Chemical cocktail polluting English rivers - MPs warn

Raw sewage, microplastics and slurry are coursing through all of England’s rivers, putting health and nature at risk, a parliamentary report concludes.

Agriculture and water companies are the biggest contributors to this “chemical cocktail”, the Environmental Audit Committee warns.

The environment minister said the report highlighted areas the government was currently tackling.

People across the country using rivers for activities ranging from sports and swimming to fishing risk falling ill from bacteria in sewage and slurry. The water and riverbanks are also home to rich plant, fish and insect life and are essential to biodiversity. But chemicals, plastics and an excess of nutrients are choking the water. No river in England can be given a clean bill of health, the group of MPs on the committee concluded after months of hearing from experts.

Budget cuts are hampering the Environment Agency’s ability to stop pollution, says the report.

“Rivers are the arteries of nature and must be protected. Our inquiry has uncovered multiple failures in the monitoring, governance and enforcement on water quality,” Environmental Audit Committee chairman and MP Philip Dunne said. “For too long, the government, regulators and the water industry have allowed a Victorian sewerage system to buckle under increasing pressure.”

Environment Minister Rebecca Pow said: “We are going further and faster than any other government to protect and enhance the health of our rivers and seas. We welcome the Environmental Audit Committee’s report which highlights many areas that this government is now tackling.”

This is a disgusting state of affairs. Time was when then the rivers were clean and the canals were dirty - it seems that the situation has reversed.

Quote from the article Omah posted: Microplastics worn away from car tyres. This statement is a load of bollox because there are NO plastics used in tyres at all.

I am surprised there is no mention of lead as a contaminant either. It is usual in articles such as this to knock anglers because of discarded lead fishing weights. However, certainly on the River Severn, it has been shown that most of the lead contamination is due to outflows from ancient lead mines that surround the Severn’s catchment.

Today tyres consist of about 19 percent natural rubber and 24 percent synthetic rubber, which is a plastic polymer. The rest is made up of metal and other compounds.

I suppose they had to dump the unused vaccines somewhere…

The following by Friends of the earth may prove interesting to you…

Although we loosely call them ‘rubber’, vehicle tyres are actually made from a complex blend of a lot of mostly synthetic materials and chemicals, including different types of plastic.

@Gee3 and @Omah Thank you both for those links. However, after spending 41 years in the rubber industry (25 of which were in direct research and development in the tyre industry), I know the difference between a rubber and a plastic. Once a rubber polymer has been vulcanised (heated for a given time), it cannot be remelted without further chemical treatments. Once vulcanised, a rubber, when stretched will, to all intents and purposes, return to its original dimensions (give or take a few % which is known as permanent set). If you melt a plastic, it can be remoulded into any shape you wish. However, if distorted in any way, shape or form, it will NOT return to its original shape, it will be permanently deformed.

Now, after many years of study, along with my vast work experience, I can tell you that:

  1. The rubber used in passenger tyre treads has, for the last 20-30 years, been a solution polymerised styrene-butadiene copolymer containing approx 35% styrene and 65% butadiene. (If you polymerise 100% styrene, you get polystyrene, which is a plastic. If you polymerise 100% butadiene, you get polybutadiene, which is a rubber (used for those very bouncy, thunder balls that were popular in the 70s and 80s but not much else on its own). If you blend the 2 monomers in the right proportions, you get very useful elastomeric (i.e. stretchy) polymers that can be used for a myriad of products including car and light commercial van tyres.
  2. Other than the tread, the tyre sidewalls usually contain a blend of natural rubber and polybutadiene.
  3. Internally, a tyre’s carcass will be polyester (plastic, textile, gets nowhere near the road) or nylon (plastic, textile, gets nowhere near the road) or a combination of the 2 along with steel wires all coated with a natural rubber based compound.
  4. The inner liner is normally either chloro-butyl, bromo-butyl, or a combination of one of these with a layer of butyl rubber compound.

Now, when a tyre’s tread runs along a road surface, it is abraded very slowly (otherwise you’d complain bitterly because your tyres wear out very quickly) and the dust formed is what both of your articles and the BBC article referred to yesterday are calling microplastics, which is totally wrong IMHO. If anything, the dust should be referred to as “microrubber” but this wouldn’t have the same cachet as microplastics.


Outstanding Percy… :+1:

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Thanks Bob :+1:

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I found it very interesting Percy, and it just goes to show the devious way in which the media report things.

I can understand Friends of The Earth coming up with crap like that because they’ve been known to use bad science many times in the past like Green Peace but I would have thought that Nat Geo would be above using it.

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A very interesting explanation from someone ‘in the know’, Percy :+1:

There are many internet sources discussing “microplastics” from car tyres - they can’t all be discredited or wrong - here’s another:

Published: 14 July 2020

Atmospheric transport is a major pathway of microplastics to remote regions

In recent years, marine, freshwater and terrestrial pollution with microplastics has been discussed extensively, whereas atmospheric microplastic transport has been largely overlooked. Here, we present global simulations of atmospheric transport of microplastic particles produced by road traffic (TWPs – tire wear particles and BWPs – brake wear particles), a major source that can be quantified relatively well. We find a high transport efficiencies of these particles to remote regions. About 34% of the emitted coarse TWPs and 30% of the emitted coarse BWPs (100 kt yr−1 and 40 kt yr−1 respectively) were deposited in the World Ocean. These amounts are of similar magnitude as the total estimated direct and riverine transport of TWPs and fibres to the ocean (64 kt yr−1). We suggest that the Arctic may be a particularly sensitive receptor region, where the light-absorbing properties of TWPs and BWPs may also cause accelerated warming and melting of the cryosphere.

Global annual plastic production reached 359 million tonnes in 20181 and, consequently, plastic pollution in freshwater2, marine3 and terrestrial4 ecosystems has received a lot of attention recently. Plastics are released into the environment as macroplastic (>5 mm)5, microplastic (1 μm to 5 mm)6 and nanoplastic (<1 μm)7 particles that can fragment into smaller sizes via photodegradation, physical abrasion, hydrolysis and biodegradation8. Plastics can affect coral reefs9, marine10 and terrestrial animals11, as well as human health12,13.

An important source of plastics is road traffic emissions14,15. Kole et al.14 reported global average emissions of tyre wear particles (TWPs) of 0.81 kg year−1 per capita, about 6.1 million tonnes (~1.8% of total plastic production). Emissions of brake wear particles (BWPs) add another 0.5 million tonnes. TWPs and BWPs are produced via mechanical abrasion and corrosion16,17.

Tyres consist of a mix of elastomers such as rubber (natural and synthetic)18, carbon black, steel cord, fibres, and other organic and inorganic components used to improve their stability19; TWPs are produced by shear forces between the tread and the road pavement, generating coarse particles20, or by volatilization generating submicronic particles21. The wearing process depends on the type of tyre, road surface and vehicle characteristics, as well as on the vehicle’s state of operation22.

Most car braking systems consist of a disc or drum with either a pair of shoes or pads mounted in callipers. Brake linings consist of binders, fibres, fillers, frictional additives or lubricants and abrasives23,24,25. Thus, BWPs are a complicated mixture of metal and plastic. BWP emissions depend on the bulk friction material23,26, on the frequency and severity of braking27, speed, weight, condition and maintenance of the automobile28 and the environmental conditions23,29,30.

Transport of TWPs and BWPs via runoff and wash-out to marine and/or freshwater ecosystems has been studied31,32. However, very little is known about their dispersion in the atmosphere33,34,35 and where they are deposited, despite their health impacts in animals9,10,11,36 and humans12,37, possibly enhanced by adsorbed toxic organic compounds and heavy metals38. Greater use of plastics results in more extensive consumption of fossil fuels and, in turn, in larger emissions of greenhouse gases39 such as methane and ethylene40. Since TWPs and BWPs can be present at sizes <10 µm41, they can remain airborne for long periods of time; different types of microplastics have been detected already in remote areas42,43,44,45,46,47. Considering that they are colourful particles48, they also absorb light and thereby decrease the surface albedo of snow and ice accelerating melting, similar to black carbon (BC)49.

Here, we examine atmospheric transport and deposition of TWPs and BWPs on a global scale (see “Methods”). For simplicity we often refer to these particles jointly as road microplastics, although TWPs and BWPs are not the only microplastics that are emitted by traffic (other sources include polymer-modified bitumen used for road pavement or road marking paint). Even though TWPs and BWPs contain components other than plastics (e.g., metals), plastics are the dominant component, especially for TWPs. We also speak of microplastics50, since we only consider the particles of mean size 0.5–9.5 µm, which can remain airborne for long periods of time.

Nothing to do with this then?
Seen in our local river (river Don)

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What is microplastic?

Microplastics are plastic pieces that measure less than five millimetres.

Some microplastics have been made small intentionally, for example industrial abrasives used in sandblasting and microbeads in facial scrubs. Others have formed by breaking away from larger plastics such as carrier bags which have fragmented over time.

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Microplastics in water

There have been many concerns about microplastic in drinking water. A recent report by the World Health Organisation (WHO) gathered data from 50 studies to clarify how serious this may be.

Microplastics enter the water system from two main sources.

  1. Run-off from land-based sources which include:
  • landfill
  • the breakdown of road-marking paints
  • debris from tyre wear
  • abrasion of synthetic products such as footwear and artificial turf
  • agricultural run-off, particularly sewage sludge and agricultural plastic such as mulching

Oh for God’s sake, how many times do I have to say it, Omah? THERE ARE NO PLASTICS USED IN TYRE TREAD COMPOUNDS therefore there cannot be any microplastics in “tyre debris”.

From the article you posted:
Tyres consist of a mix of elastomers such as rubber (natural and synthetic), carbon black, steel cord, fibres, and other organic and inorganic components used to improve their stability;

That is a pretty good summary of what a tyre tread contains. You will notice that there is no mention of plastic materials in the list. One thing that is missing - modern passenger tyre treads contain a significant proportion of silica which is added to reduce the rolling resistance and improve fuel consumption.

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Well, don’t argue with me … argue with those who know better than you … :wink: