Beech and climate change. Beech trees are important (ecologically and financially) in the woodlands and forests across Europe.  Beech has a wide distribution from Southern Europe up into Scandinavia.  However, the beech has a relatively shallow root system and this makes it susceptible to drought.  In recent times, as a result of climate change, extreme weather events such as drought have become more common.  Analysis of beech tree rings (from 5000+ trees) across Europe suggest that whilst those Sweden and Norway are growing quite well those in Southern Europe are not, in fact growth may have declined by as much as 20%.   Current climate projections suggest that beech growth / productivity in southern areas may decline further, with increasing mortality. Warning signals. Many animals are able to send signals to other members of their species warning them of imminent danger, such signals can be warning sounds or ‘scents’.  The scents may be in the form of pheromones, essentially ‘airborne hormones’. Now there is growing evidence that plants may be able to act in a similar way.  For example, if mint leaves are damaged by a insect herbivore attack, then field mustard and soybean plants growing in the vicinity respond to the volatile chemicals released by the mint and activate their leaf defence systems (this often involves creating an unpalatable taste).  The volatile compounds released (during damage) are ‘oils’ or terpenes, like  β-Ocimene.  β-Ocimene has a sweet, woody fragrance but it is not clear how it stimulates other plants into activating the genes for their defence mechanisms.   Research is underway at the Tokyo University of Science. Lead and Birds of Prey.  Birds and Prey feed upon flesh they scavenge (like the entrails of deer, or dead pheasants) or from animals they capture.  The trouble is that often this flesh is riddled with bits of lead shot.  Lead is a poison, and is not easily eliminated from the body.  Animals injured by lead shot may suffer a slow and agonising death. Those that feed upon them also accumulate lead in their bodies, which affects their physiology and behaviour. Now Cambridge based scientists have studied the lead levels in a variety of birds of prey.  They looked at lead levels in the livers of some 3000 raptors. Birds, like eagles, are worst affected as they are long lived, breed later in life and rear relatively few young per year.  For a number of species, they have been able to estimate the % reduction in population size that the lead is responsible for. Species Estimated % loss of population White tailed eagle 14 Golden Eagle  13 Griffon Vulture 12 Red Kite & Western Marsh Harrier 3 Buzzard populations are estimated to be 1.5% smaller, which may not seem much but it equates to the loss of some 22,000 birds. Lead is still used in shotgun cartridges, many pheasants are still  killed with lead based ammunition, despite requests to hunting groups to switch to non-toxic gunshot (by 2020).  Full details of this work can be found here. Warmer autumns and butterflies. Green veined white butterflies are common in the U.K. and Europe.  Researchers in Sweden have been looking at how they might respond to warmer and longer autumn weather.  Under laboratory conditions, they exposed the chrysalises (over-wintering stages) of the butterfly to warmer autumnal conditions.  They found that the chrysalises used more energy and lost more weight under these conditions, and were less likely to survive to the adult / imago stage in the following Spring.  With global warming affecting our climate, it could be that populations of this butterfly could struggle as time passes.

The woodlands blog has previously reported on the worrying decline in insect numbers, but there has been yet another report detailing significant falls in the populations of (flying) insects.  This survey was run by Buglife and the Kent Wildlife Trust  (KWT) using a smart phone app - “Bugs Matter”. The survey suggest that between 2004 and 2021 the number of flying insects (in Kent) has fallen by some 70%.  This finding is not dissimilar to that carried out in rural Denmark which found an 80% decline in insect numbers between 1997 and 2017. Insects are vital to the functioning of ecosystems.  They help maintain: A healthy environment Contribute to the recycling of organic matter Act as pollinating agents Help control pests Without insects the ‘web of life’ begins to fall apart.  The loss of insects and other forms of wildlife can be helped by: Creating larger areas of natural habitats (many have been lost to roads, agriculture, urban expansion) Creating wildlife corridors to link up similiar habitats / ecosystems throughout the landscape Creating wild flower ‘meadows’ by road sides, verges etc Reducing the use of pesticides and other chemicals which have significant effects on wildlife The Buglife survey makes use of a simple technique to estimate insect abundance - the ‘splatometer’.  This involves counting the number of ‘squashed’ insects on car registration plates.  The Danish survey used a similar method but looked at insects found on car windscreens.   This summer Buglife is hoping that people will again contribute to another survey using the splatometer technique.  The survey will run from June 1st to August 31st.   To contribute to the survey you will need :- The “Bugs matter” app (free) and a smart phone. To create an account to send in your results Clean the car number plate before the start of any journey in your vehicle At the end of your journey, count the number of squashed insects on the number plate (using the splatometer grid - which will be sent to you) and take a photo. This enables Buglife to calculate the ‘splat rate’, that is the number of insects recorded per mile.  NB.  Journeys on wet days are not recorded as rain might wash off any insects from the number plate.   The more journeys and counts that you can carry out the better, and zero counts of squashed insects are just as important as those with an actual number of squashed insects. Note : The app includes a tutorial and some safety advice. It is available for android or apple phones.

There’s a seemingly endless stream of bad news in the world: the coronavirus pandemic has forced us stay inside more than we’ve ever had to in our lifetimes, and there’s the ever-impeding threat of the climate crisis. Our collective mental health is suffering, and more than ever we’re looking for anything that can provide some alleviation from this.  The government recently found that almost half of the UK’s population say they are spending more time outside than they did before the pandemic, so it’s clear that green spaces are more important than they have ever been for both our own wellbeing and the wellbeing of our planet, which really begs the question ‘why not plant more trees?’  Why is tree planting good for the environment? Forest ecosystems are one of the world’s greatest carbon sinks in existence. They hold up to 45% of all the carbon stored on land, as well as being home to 80% of the animal and plant life on land. Maintaining our forest ecosystems could be one very large step towards solving the climate crisis; and though this won’t be enough on its own, it’s definitely a good place to start. On a smaller scale, one hectare of young woodland  has the ability to lock up over 400 tonnes of carbon.   Imperial College estimates that a tree planting initiative on a worldwide scale could capture the equivalent to one decade’s worth of carbon emissions (at current rates) by the time these forests reach maturity, or up to 1/3 of all emissions from human activities that remain in the atmosphere since the Industrial Revolution. How can tree planting can benefit you? Local tree planting initiatives are an excellent means of drawing a community together. Forest For Peterborough, a tree planting organisation in the UK, started in 2010 with the aim to plant 230,000 trees by 2030, and at the same time provides a space where the community can come together and learn how to make responsible and sustainable choices. In 1980 Edward O Wilson, American biologist, popularised the term biophilia to describe the innate connection people have to the natural world, and it’s true that we as humans seek and crave the comfort of the natural world, particularly in times of stress. The UK government estimates that visits to UK woodlands have saved an estimated £185 million in mental health treatment and costs. At the same time, street trees in rural areas are thought to have avoided £16 million in antidepressant costs, so why are there not more trees being planted in rural and urban areas? More local tree initiatives like Forest For Peterborough could both help save people’s mental health and help the UK government reach their target of becoming carbon neutral by 2050. Planting trees can also help with our physical health. It goes without saying that having poor mental health can begin to have an impact on our physical health, and vice versa (in fact, loneliness has the same affect as smoking 15 cigarettes per day), and having green spaces near our living areas helps to improve our attention and creativity. Walking amongst trees even boosts our immune system and reduces our cortisol levels. It’s also been shown that in areas affected by tree loss, women have a higher risk of cardiovascular disease (222,000 hectares of green space have been lost to urban sprawl between 2006 and 2012 in the UK) and senior citizen’s survival rate is 17% higher if their residence is within walking distance of a green space.  Planting trees can even help your wallet, too (maybe money does grow on trees!). Aside from saving the UK government millions of pounds in mental health costs and the projected costs that could come with the climate crisis in future, planting trees next to buildings can reduce the buildings’ energy consumption by up to 26%. This lowers the buildings’ internal temperature by 4 degrees in the summer and increases it by 6 degrees in the winter, so there’s less of a need for central heating and cooling systems (and of course prevents further emissions into our atmosphere). House prices rise by 9 to 15% if they’re near trees: they add to the aesthetic value of a neighbourhood, make people feel safer, and have been proven to lower crime rates. Why not plant trees? So, why plant trees? If planting trees for the sake of the planet isn’t enough of a reason, then there are plenty of ways tree planting can help you and your community. If you’re looking for tree planting opportunities there are plenty of events coming up, such as National Tree Day, which this year will be celebrated on July 31st. For the Queen’s Platinum Jubilee a tree planting initiative - The Queen’s Green Canopy- will encourages people across the UK to 'Plant a Tree for the Jubilee.’  Tree planting land for sale is available through the Woodlands website- let’s get planting!

May Fungi Focus - Campion Anther Smut  Spring is busting out all over, a time of fresh growth and new life. The past few months have seen a succession of our native woodland flora coming into their own; first woodland anemones then bluebells and primroses and now Ramsons  (wild garlic) and arums like the majestic Lords-and-Ladies or Cuckoo Pint. Amongst all this vibrant colour, it almost seems perverse to let ones thoughts wander to fungi, in most minds associated with death and decay.  Nevertheless, there are whole swathes of species that make their homes on the living tissue of plants. The rusts, for example, are particularly conspicuous at this time of year when such early bloomers begin to die back. Many are specific to one plant, or jump between different species at different stages in their own and their host’s lifecycle. Identify the plant, and most of the time you can identify the rust. Wherever you find Alexanders, for example, you are likely to find Alexanders Rust (Puccinia smyrnii). Wood anemones play host to Tranzschelia anemones, while the orange circular blotches you can see on the leaves of Lords-and-Ladies (Arum maculatum) and Ramsons (Allium ursinum) are most likely caused by Arum Rust (Puccinia sessilis). In a previous two-part post, I’ve covered Bluebell Rust (Uromyces muscari), that usually appear just before the leaves begin to die back (part one can be read here and part two here), while I’ve also written about Blackberry Leaf Rust (Phragmidium violaceum), and Dock Leaf Rust (Puccinia phragmitis), this latter an example of a species that overwinters in a different form on a different host, in this case Common Reeds. Rusts are described as parasitic and pathogenic. For certain cash crops, host-specific rusts can cause havoc in commercial monocultures. The examples I’ve outlined above, however, might be considered opportunists whose lifecycles have evolved to fit in with their specific ecosystems. Needless to say, there are many, many species of rusts, and precious few people paying attention to them. [caption id="attachment_38169" align="aligncenter" width="675"] Beauty is in the eye of the beholder: Arum Rust on the underside of an Arum leaf.[/caption] This is even more the case of smuts. While some might argue that, for example, the circular arrangements of blisters of Arum Rust have a certain organic beauty, in the Haeckelian sense, few would make such a case for smuts. Rusts target the leaves or other greens part of plants, often manifesting themselves as their hosts die back. Smuts head straight for the reproduction organs – fruits, seeds and stamens. They are not called smuts for nothing. The name derives from the German for dirt, and indeed, they manifest themselves in thick coatings of dark brown to black spores (teliospores, to be specific, but there’s no need to go into the particular details here), transforming the parts of the plant they grow on into a dark sooty mass. Much of the attention focussed on them is on species that have commercial ramifications (again, like the rusts). Ustilago tritici, for example, affects the seeds of the cereals wheat and rye, and can result in serious crop losses. Unsurprising then that it should be one of the very few species detailed in the pages of Læssøe and Petersen’s Fungi of Temperate Europe. It would be a tough argument to make that smuts present much in the way of benefit to mankind, although it is worth mentioning that in Mexico, there is one species whose presence is more welcome: the Corn Smut (Ustilago maydis) transforms the kernels of maize into a delicacy known as huitlacoche. However, there are around at least hundred different smut species in the British Isles, and most are as common as the host they grow upon. This month’s Fungi Focus is on the Campion Anther Smut (Microbotryum violaceum), one of the most commonly reported and easiest to find, as Red Campion itself is in itself a very widespread native plant that pops up alongside roadsides, pathways and hedgerows to brighten up the summer months with its pink-red flowers. As should be clear from its name, this smut targets the anthers*, so can be spotted from a distance as the centre of the flowers will be a sooty brown to purplish-black colour (hence the ‘violaceum’ part of its name’) instead of the usual light pink, the stamen and anthers coated with this spore mass. [caption id="attachment_38171" align="aligncenter" width="675"] As nature intended? An un-smutty Red Campion.[/caption] While this smut adds little cosmetic appeal to the flowers, the teliospores do present a certain fascination when viewed under the microscope; spherical and ranging from 6-10microns in diameter, and covered in an intriguing pentagonal reticular pattern. The smut transfers itself to other plants by pollinating insects who would otherwise be involved in aiding the reproductive process of the campion itself. Smuts might be viewed as a sort of horticultural STD.  Nevertheless, the ubiquity of campion flowers at this time of year would suggest that this smut does not have a particularly negligible effect on the fecundity of this particular species. Indeed, from my own observations over the years, it is rarely that present even in areas rife with campion and when it does appear, it is localised to handful of plants. [caption id="attachment_38172" align="aligncenter" width="675"] The teleospores of Microbotryum violaceum, or more specifically,  M. lychnidis-dioicae.[/caption] Microbotryum violaceum is one of the more regularly recorded of the smuts that grown on the native plants of the British Isles, and as such one should consider it a native species in its own right.   In fact, more recent investigation has shown just how specialist it is. While I’m still using the old catch-all term for the sake of simplicity, it has been split up to create several more host specific ones: M. lychnidis-dioicae is the new name to describe the smut occurring on the anthers of Red and White Campion; M. coronariae appears on Ragged-Robin; M. saponariae on Soapwort; M. silenes-inflatae on Sea Campion and M. stellariae on Lesser Stitchwort. But one does have to ask oneself just how many people out there would consider a smut even worth recording. As specialist plant pathogens, individual species of smuts can be considered as rare or as common as their host plants, and with many native plants themselves under threat from habitat loss, their associated smuts suffer accordingly. Interestingly, according to a recent publication compiled by Ray Woods, Arthur Chater, Paul Smith, Nigel Stringer, and Debbie Evans entitled Smut and Allied Fungi of Wales A Guide, Red Data List and Census Catalogue (2018), “No smut species are specially protected under the Wildlife and Countryside Act 1981 but a single smut species (Urocystis colchici) found on Autumn Crocus (Colchicum autumnale) is listed on Section 7 of the Environment (Wales) Act 2013 as being ‘a living organism of principal importance for the purpose of maintaining and enhancing biodiversity in relation to Wales’.” The same publication lists the example of Urocystis ulmariae, found only once in Wales on a single Meadowsweet plant, and placed it in the “Critically Endangered D2” category. The fascinating The Lost and Found Fungi Project, conducted by mycologists at Kew Gardens to investigate whether historically reported fungi species that have not been recorded in recent years are actually extinct or just not recorded, has also focussed on Rusts and Smuts. It is worth a look just as an example that there is some interest in smut distribution and conservation.  One might question the worth of recording, studying or conserving fungi species that so evidently hamper the reproductive abilities of their hosts. As ever, I’d argue in these posts that until the funding and human effort is put into such endeavours, we will never know. * anthers - pollen producing part of the stamens. Wild garlic

We know that insects (especially, bumblebees, bees, hover flies) are the world’s top pollinators, and we also know from many reports that many insect species are in decline.  Crops such as tomatoes, blueberries, peppers, cocoa, coffee, almonds and cherries are dependent on these pollinators.  Climate change, increasing temperatures and extreme weather events are affecting plants and animals across the world, and it seems that social insects, like bumblebees, are particularly impacted. Research with bumblebee colonies (at Stockholm University) has indicated that if the colonies are exposed to higher temperatures (than normal) then the workers in the colonies were smaller.  This decrease in body size could affect their foraging behaviour and the collection of pollen,  which would mean less food brought back to the colony and reduced pollination of plants. Studies in the United States looked at some 20,000 bees  (bumblebees, leafcutter bees, mason bees etc) along the Rocky Mountains, a region which is vulnerable to climate change.  It was found that the larger bees (particularly bumblebees) and those that built nests with combs were affected most by increases in temperature.  On the plus side, smaller (soil nesting) bees fared better.  Bumblebees would seem to have a lower heat tolerance.  The loss of bigger bees, which generally can fly and forage further may again mean reduction in long distance pollination (which promotes outbreeding in plant populations). One reason why hot or hotter weather affects bumblebees is that it influences the nectar that the bumblebees collect.  The balance of the various micro-organisms (bacteria and yeasts) in the nectar changes.  Whilst bumblebees are attracted to nectar with some microbes in it, a small change in temperature can speed up the metabolism / growth of the microbes so that they use up more of the sugar - with the result that it is less palatable / less nutritious for the bees.  Experiments conducted at the University of California have shown that bees did not ‘like’ the nectar rich in microbes, nor a sterile one - with no microbes at all. There seems to be a 'happy medium' in terms of the composition of the nectar. There seems to be a growing consensus that climate change, increasing temperatures and extreme events are pushing bumblebees (in particular) beyond their physiological limits. [caption id="attachment_38081" align="aligncenter" width="650"] Bumblebee visiting foxglove[/caption]

Certain woodland plants are found in the understory.  Plants like wood anemones, woodruff and lungwort bloom early in the year. These plants make use of a ‘window of opportunity’ when the light levels are good as the tree canopy has not developed, the leaves have not yet expanded. They use this ‘window of light ‘ to flower.   However, climate change is affecting many ecosystems - including woodlands.  With warmer temperatures, leaf buds tend to open earlier and the leaves begin to expand.  If the window for growth is reduced, how can the wood anemones and others cope ? [caption id="attachment_38093" align="aligncenter" width="700"] wood anemone[/caption] To investigate this question, scientists based the Universities of Tübingen and Frankfurt examined thousands of preserved herbarium specimens of early flowering plants, dating back over a hundred years.  The sheets not only hold specimens collected when they were flowering but also have  information on ‘when and where collected’.  Each sheet is a a moment in time from over a century ago.  Collectively, the 6000+ sheets allowed the scientists to establish historic flowering times of woodland plants over large areas of Europe. [caption id="attachment_38094" align="aligncenter" width="700"] Woodruff[/caption] The information extracted from the herbarium records revealed that plants like wild garlic and wood sorrel now bloom some six days early than at the beginning of the twentieth century.  For each 1oc rise in (Spring) temperature, their lowering has advanced by more than 3 days.  This means that they have gained time in the light - in an open canopy.  Whilst they may have gained time,  these early flowering plants are at greater risk of frosts.  It may also be that their pollinating agents may not be around - unless they too have brought forward their development / life cycle. There is some evidence that such changes are taking place.  Recent work at Wytham Wood (outside Oxford) has shown that blue tits have moved forward their egg laying to 'match' the development of the oak canopy, and the appearance of caterpillars (on which the young are fed).  Essentially, the timing of the food chain has changed..  Hopefully, such changes will occur in different ecosystems across the country.

LASI is the Laboratory of Apiculture and Social Insects at the University of Sussex. It is particularly noted for its research work on bees. Recently, Dr Balfour and Professor Ratnieks have published a study on the rôle of certain 'injurious weeds'.   Five of our native wildflowers fall into this category : Ragwort (Jacobaea vulgaris), Creeping or Field Thistle (Cirsium arvense), Spear or Common Thistle (Cirsium vulgar), Curly Dock (Rumex crispus), and Broadleaved or Common Dock (Rumex obtusifolius).  They compared the ragwort and the thistles with plants like red clover and wild marjoram (often encouraged / sown on field edges etc).. They found that the 'injurious weeds' were particularly 'effective' at attracting pollinators, not only did they they attract greater numbers of pollinators than clover etc, but also a greater range of pollinator species.  This was ascribed to the open nature of their flowers and their generous nectar production.  This brings into question the control of species like the ragwort, as it is clearly important to pollinators (as are some 'botanical thugs' - like brambles).  Ragwort contains chemicals that are toxic to livestock, causing liver damage; it has been blamed for the deaths of horses and other animals. At the Smithsonian, Kress and Krupnick have analysed the features of some 80,000+ species of plants to see how they might fare in the Earth's changing climate (the Anthropocene).  This may seem like a large number of different plants, but represents approximately only 30% of the known species of vascular plants.  There is not enough information of the remaining species to make a reasonable guess as to how they might react to climate change;  a reflection on how little we actually known about our 'botanical resources'.  Sadly, they conclude that more plants will lose out than win.  Particularly at risk of extinction are the Cypress family (which includes the redwoods and junipers) and  the Cycads, whereas black cherry might be a winner. As was reported previously in the woodlands blog, there is a difference between the leaves of the redwoods found at the top of the tree and those lower down.  Those at the top are small, thick, and fused to the vertical stem axis; this fusion of leaf and stem creates a relatively large volume of tissue and intercellular space that can store water. The leaves in the lower part of the crown by comparison are large, flat and horizontal to the stem axis.   Now scientists as the University of California (Davis) have further investigated the role of these leaves.  They now believe that the different leaf forms help explain how the exceptionally tall trees are able to survive in both wet and dry parts of their range in California.  In the rainy and wet North Coast, the water absorbing leaves are found on the lower branches of the trees.  In the Southern part of the redwoods range, the water collecting leaves are found at a higher level to take advantage of the fog (and rain, which occurs less often).

In the C19th, many objects were made from ivory.  The ivory came from the slaughter of elephants.  As elephant populations fell, so the search for a suitable substitute began.   Celluloid was one of the first materials used but it was easily combustible. It was soon replaced by other materials like Bakelite,  this was the first entirely synthetic plastic.  It was made from phenol and formaldehyde.  It was used for toys, radios, telephones etc.   Bakelite  was tough, heat resistant and  did not conduct electricity.  Other materials followed, and many different plastics are produced today; for example, polyethylene (which is widely used in product packaging) and polyvinyl chloride [PVC] (which is used in construction and pipes because of its strength and durability).  The trouble is that plastics are just so useful.  Plastics are cheap, lightweight and durable.  Durability is a good quality when the plastic is being used but not when it is discarded, for example, into landfill where it may take centuries to degrade.  Sadly, many consumers leave empty bottles / containers / wrappers in the streets, on the beach, at picnic sites etc.  As most plastics are made from fossil fuels / oil, the manufacture of plastic is also a driver of climate change. Since the middle of the twentieth century, it is estimated that some 8.3 billion tonnes of plastic has been produced. Sadly much of this has ended up in landfill, in rivers, the soil, and the oceans - with significant effects of wildlife. Plastic pollution is ubiquitous. For example, the Great Pacific Garbage Patch, which is a collection of large areas of plastic and other debris in the North Pacific Ocean. It has been estimated that it contains some 1.8 trillion pieces of plastic .  It is a serious threat to marine life such as whales, sea turtles, fish, and birds.  Plastic items are discarded with little thought to the consequences.  Bottles etc can end up as traps for many animals and a few years back we (at woodlands) found a child’s plastic boat dumped in a woodland (see featured image above).  Sometimes, we see the distorted remains of plastic tree guards ‘strangling’ young trees. Plastic carrier bags (sometimes filled with dog faeces)  can end ups suspended from trees / shrubs in woodland, or caught on wire fencing, waving n the wind. Discarded plastic items come in all shapes and sizes; those that are 5mm or smaller are termed “microplastics.”  Microplastics come in part from larger plastic pieces that degrade into smaller pieces; but also from microbeads.  Microbeads are very small pieces of polyethylene plastic that are added to health and beauty products, such as some skin cleansers and toothpastes. Now microplastics are to be found everywhere from deep oceans, to Arctic snow and Antarctic ice.  They are found in foodstuffs and drinking water.  One investigation found that if parents prepare baby formula by shaking it up in hot water inside a plastic bottle, their child might swallow tens of thousands of these microplastic particles each day.  The movement of these particles through ecosystems is  graphically summarised in this article.   There is currently much discussion and research about how these microplastics will impact on the environment and different organisms, including us.  Because they are so small and to be found widely in the environment,  they enter organisms and food chains.  Apart from the plastic in these particles, they may also contain chemical residues of  plasticisers, drugs, and pharmaceuticals, and heavy metals may stick to them.  Sometimes, sewage sludge may be used as fertiliser and this can contain nanoplastics.   Also, treated wastewater is used for irrigation  purposes and this again may be a source of plastic.  Research indicates that earthworms in microplastic ‘enriched’ plant litter grow more slowly and have a shorter life span, and there is evidence that the gut of earthworms becomes inflamed after exposure to microplastics.   Earthworms are important in aerating the soil and transporting materials such as dead leaves from the surface to deeper in the soil, they also 'inadvertently' transport micro-plastics.  Springtails, a group of soil micro-arthropods (Collembola) can also help move micro-plastics in the soil.  The movement of microplastics through the soil makes these materials ‘accessible’ to other soil dwellers but it is not clear if they pass along food chains (as has been the case with pesticides). Whether nano-plastics are taken up by or affect plants - again is not yet clear.  However, the chemicals released by plastics such as phthalates may taken up by plants. There is a significant risk of physical and physiological damage to organisms and ecosystems by these micro-plastics *. The particles also get into the human body and the consequences for our health are, as yet,  unknown. further information on nanoparticles etc : https://www.sciencedaily.com/releases/2022/04/220420133533.htm