Nobel Prize for Oxygen Sensing and Hypoxia: the Environmental Relevance of Phenomena

Tiistai 8.10.2019 klo 9:37 - Mikko Nikinmaa

One of the most conspicuous changes that occur in the aquatic environment is the increasing occurrence of hypoxic areas. The Nobel Prize in Physiology and Medicine is this year given to three scientists, Kaelin, Ratcliffe and Semenza, who have studied and discovered the mechanism of how oxygen deficiency controls gene expression in man. Compared to air-breathers, fish and other aquatic animals must get by with 1/30th of the oxygen concentration. They are further faced with marked variations in oxygen level both daily and seasonally (or unknown periods of time). Further, since fish are poikilothermic, temperature changes affect their oxygen requirements conspicuously.

The oxygen sensing and transport system of fish must therefore be more vHIF.bmpersatile than that of mammals. We have studied the oxygen sensing and hypoxia-inducible factor (HIF) system, i.e. the phenomena now awarded Nobel Prize, since the late 1990’s. First, we observed that hypoxia-inducible factor was present in cells already in normal venous oxygen tension, although it increased in hypoxia (in humans and laboratory rodents it is only found in hypoxic conditions). Second, we observed that although the hypoxia-inducible factor level was controlled posttranscriptionally, also gene transcription could be modified. The HIF transcription depended on the number of hypoxic bouts experienced by the animal (in humans the control of HIF level occurs posttranscriptionally). Finally, we observed that HIF level was affected by temperature (something that is irrelevant for us homeotherms). These facts, together with the observations of interactions between HIF and circadian rhythms and environmental pollutants show that the system given the Nobel Prize for is more versatile in poikilothermic water breathers than humans.

Given that oxygen is a limiting factor in aquatic environment, it is no surprise that HIF system in fish has evolved differently in different fish groups depending on their oxygen requirements. In continuation, the possibilities of fish to adapt to climate change and environmental pollution are markedly affected by what their HIF system is. Thus, the Nobel Prize winning studies have a significant environmental angle. This has been reviewed to some extent in Nikinmaa, M. and Rees, B.B. (2005) Oxygen-dependent gene expression in fishes. Am. J. Physiol. - Regul. Integr. Comp. Physiol. 288, 1079-1090 and in Prokkola, JM and Nikinmaa M (2018) Circadian rhythms and environmental disturbances - underexplored interactions. J. Exp. Biol. 221, jeb179267. The evolution of HIF system in animals was explored in Rytkönen KT et al (2011) Molecular Evolution of the Metazoan PHD–HIF Oxygen-Sensing System. Mol. Biol. Evol. 28: 1913-1926.

Kommentoi kirjoitusta. Avainsanat: climate change, temperature, hypoxia, evolution, environmental pollution

Iron availability limits well-being of fish in open oceans?

Maanantai 16.9.2019 klo 11:46 - Mikko Nikinmaa

Iron is essential for production of haemoglobin and many enzymes (e.g. cytochromes, which include most detoxification enzymes). It is known that iron availability is very low in some parts of the open ocean, notably the Southern Seas, areas around Antarctica. It is also known that iron availability limits phytoplankton growth in the oceans. A recent article in Frontiers in Marine Science (Galbraith et al (2019) Growth Limitation of Marine Fish by Low Iron Availability in the Open Ocean. Frontiers Mar Sci 6:509) argues quite convincingly that this may be the case also for fish. One of the good points made by the authors is that the icefish without haemoglobin have only evolved in the iron-poor waters of Antarctica, not in the much iron-richer Arctic waters, although the temperatures in both are the same, and the low temperature is usually used as the reason for the possibility to the evolution of icefish devoid of haemoglobin. If the evolution has been just a random event, the question remains: why has not this random event taken place in the Arctic? Now, because the low temperature allows it, the haemoglobinless icefish benefits immensely from not having to produce haemoglobin. Compared to fish with haemoglobin, its iron requirements are about 20 times smaller, enabling it to live comfortably in iron-poor environment.

If iron availability limits the well-being of fish, it also causes problems with pollutants requiring cytochrome-dependent detoxification. Usually the detoxification system produces more cytochromes upon toxic insults. However, this may be difficult or impossible for species living in iron-poor areas. If this is the case, pollution of the Southern Seas may be a much more serious for fish inhabiting the area than, e.g. for fish living in North Atlantic.

Kommentoi kirjoitusta. Avainsanat: environmental pollution, icefsh, low temperature

Cigarette Butts - a Major Source of (Micro)plastics

Sunnuntai 28.7.2019 klo 20:37 - Mikko Nikinmaa

In about 1970 a survey was made in Finland about the different types of trash in the environment, and I made a similar survey on the roadsides and beaches of South Wales. The most common type of trash was cigarette butts. At least 80 % of smokers have thrown smoked cigarette butts to the environment. They may not be as visible as larger trash, but as already the early surveys indicate, easily found, and in beaches a significant nuisance just as trash.

However, cigarette butts are not just a nuisance. Cigarette filters are plastic. Apart from tyre wear particles they are probably the most important source of aquatic microplastics. The problem with plastics from  cigarette filters is that they have high concentrations of all the toxins that cigarettes have. Since the toxins, e.g. the ones causing lung cancer in humans, are lipophilic, they adsorb to the plastics in the filters, and even when the filter is broken up to microplastics remain attached to the plastics. This means that whenever animals eat plastic particles, they will get much toxic compound, which are easily absorbed in the intestine, where lipophilic compounds easily cross intestinal epithelium. This “Trojan horse”-type behaviour makes the cigarette butt-derived microplastics much worse pollutants than any other plastics even if other plastic particles can also have smaller amounts of adsorbed harmful substances.

Pictures of ingested cigarette butts in fish intestine have been circulated. However, small microplastic particles are ingested by planktonic organisms such as early life stages of fish and water fleas. It has been shown that fish development is disturbed by cigarette butts, and indicative of the harmful toxins being involved, the developmental disturbances are more severe for smoked cigarette butts than for unsmoked ones (Lee & Lee 2015. Ecotoxicology and Environmental Safety 113, 362-368). With regard to zooplankton such as daphnia, they ingest microplastics, and ingestion of microplastic particles can cause at least experimentally induced population decreases (Bosker et al. 2019. Environmental Pollution 250, 669-675).

So tobacco smoking affects also environment and people, who are not in any contact with smoke. In the plastic pollution, it is an important component, I would say a major one in Europe and North America. Furthermore, it could be completely finished: stop smoking or if you cannot do that, do not throw your cigarette butts in environment.

Kommentoi kirjoitusta. Avainsanat: environmental pollution, aquatic toxicity, conservatio

Global Environment Tax - for the Survival of the Earth

Sunnuntai 9.6.2019 klo 18:08 - Mikko Nikinmaa

It is an undeniable fact that the Earth’s resources and possibilities for production are overused. Another indisputable fact is that the wealth in the world is very unequally distributed. A third fact almost universally accepted is that companies move their production to cheap countries and that companies and individuals often go to great lengths to pay as little tax as possible. These facts have resulted in the most inappropriate response that is possible: the rise of populism striving for nationalistic isolation. The solution could have been appropriate a hundred years ago with less than two billion people, virtually no mass communications and no means for rapid transport possible for common people. However, today we must accept that we live in one world, and that what is happening in, e.g., India will affect us in, e.g., Scandinavia. It doesn’t help us much if we can say that “our nation has done everything correctly, but we are going under because other nations have not done enough”, when the environmental problems such as climate change, environmental pollution and food shortages make life intolerable.

Thus, only global solutions can be sustainable. However, up to now globalism has only been associated with favouring the rich. All the international negotiations have had the dividing line between developed and developing nations. Both outsets must be changed if we will have sustainability and will leave habitable Earth to our grandchildren. A balanced solution to this would be a progressive global environment tax (GET). The funds collected this way would be used for urgent environmental needs throughout the world. Below a certain adjusted (one needs to take into account absolutely necessary expenses required for warming the houses and clothing that differ between warm and cold climates) level of income there would be no tax, and tax would be increased with income. This would ensure that inhabitants from low- and high-income areas would pay justified tax. The tax should also be paid from property to make it impossible toIMG_20170725_0053.jpg evade the tax by, e.g., investing in stock market. Further, since the tax would be global, companies could not evade it by transferring operations to low-tax nations. A question, which also has to be solved is how different nations would pay the global tax, since their involvement in the overall economy differs. The simplest solution, again taking into account the different wealth of nations, would be to have the contribution as gross national product divided by population. It would be imperative for nations to be required to contribute to the global tax fund, since they have very different roles in overall economy. Since a major environmental problem is that the world population has increased beyond what can be tolerated, the average number of children should somehow be taken into account. This could be done by including in the nation tax average number of children. The nation’s contribution would be increased, if the number of children exceeded the number calculated for a stable population. As no nation would be exempt from the nation-wide payment, this would ensure that the population contribution would be paid also by countries, where most of the inhabitants would be exempt from payment. GET would be collected by the United Nations: UN already has all the world’s nations included.

Utopia? Probably, but environmental deterioration (which includes climate change) is the major enemy of every person living on the Earth. Consequently, combatting climate change should be given a high priority in allocating defence budget funds. All the nations in the world could easily pay a significant sum of money to GET – and doing that would actually decrease the need for traditional defence spending. Besides, having large defence budgets do not help much if there is nothing to defend any more. Utopia, maybe, but we need these kinds of solutions in order to give a habitable Earth to our grandchildren.

Kommentoi kirjoitusta. Avainsanat: climate change, environmental pollution, developmental aid

Growth Economy - Enemy of Habitable Earth

Keskiviikko 22.5.2019 klo 20:29 - Mikko Nikinmaa

Throughout the world politics is centered around maximal economic growth. When the economic growth of a nation is smaller than the average, the politicians and the media are depressed and almost think that the end of the world has come. However, that is not the cause of the end of the world, but growth itself is.

Analogy to maximizing economic growth is a car with no visibility - one does not know what happens if you increase the speed. The earth is the car with no visibility. In the case of driving a car, with decreasing visibility, you decrease the speed to enable you to respond to any problem. You certainly would not increase speed, but that is what is done with economic growth. One does not know what happens to the Earth, but growth must be speeded up. The concepts of growth economy were formulated when the human population was one fifth of what it is now and there seemed to be unlimited space and resources.

This is not the case any more. The human population is so large that it inevitable leads to the use of land, energy and resources in such a way that the future use is affected. As two negaive results of this we have climate change and biodiversity loss. Despite the clear negative effects of growth, both population and economic growth are the primary goals of politics. It seems almost impossible for politicians and other decision makers to realize that they are behind all the problems that the right-wing populists are utilizing. If the resources and space were unlimited, there would be no refugees, no climate change etc. So continuing with the concept of growth is plain silly.

The growth has been possible by taking a loan from nature, i.e. a loan from future generations. This is not sustainable. So the concept of natural capital must be introduced into main focus of political and economic thinking. The outset of any political and economic decision should be that anything done is neutral to the environment (if a decision causes a deterioration of one aspect in environment steps should be made to compensate for it in other environmental features).

If we decide to accept that growth is changed to zero effect on environment, the problem is that many negative effects of growth will continue for a long period of time. If, for example, we are able to decrease the number of children to a level that in the long run will stop population growth, the population increase will continue for the period of time that the present children grow up to fertile age. Similar examples can be found in virtually all aspects of life. However, we must not resort to thinking that the lack of effects in the short term shows that the measure is not effective. What we need to do is putting all our efforts to change from growth economy to sustainable solutions.

Kommentoi kirjoitusta. Avainsanat: natural capital, cliamte change, environmental pollution

Our Planet

Lauantai 11.5.2019 klo 18:35 - Mikko Nikinmaa

The Our Planet documentary series by David Attenborough in Netflix (www.ourplanet.com) is incredibly good, and will probably be the most popular pro-environment series that has recently been published. When watching it a couple of things must be remembered. Although climate change is of a huge concern, the short-term solutions alleviating it will not solve the basic problem, which is our overuse of the planet. Climate change is just one symptom stemming from the facts that there are too many people who are overusing Earth's resources. In November 2, 2018 I wrote a blog, where pictures of human population change and the increase of world's carbon dioxide were side by side. And they could be superimposed. Further, although it could be possible to severe the link between human population and carbon dioxide production in the short term, the vicious circle between population growth, resource overuse, pollution and climate change still exists in longer term because of the following.

Human population needs to be fed. The intensive agriculture with artificial fertilization and pesticide use has increased the agricultural production per hectare to 5-10 times the crops obtained before "industrial" agriculture. It has been estimated that without the use if artificial fertilization and pesticides the maximal size of human population would be 2-3 billion. However, Nature presently strikes back. Fertilization pollutes our waters, pesticides kill pollinators and the microalgae of the seas. The results arte that aquatic pollution is decreasing the ability of algae to photosynthetize. The aquatic algae have contributed to 50 of the carbon dioxide sinks of the world. Now it is estimated that carbon dioxide fixation by them has decreased by 20 %. Aquatic pollution thus drives climate change.

Pollinating insects die as a result of insecticide use. Since about 2/3 of all the food plants need pollination by insects, this as such reduces the possibilities of increasing agricuDSC00354.JPGltural production by increased insecticide use. As the productivity per hectare cannot be increased, more people means that forests must be cut to obtain agricultural land. At the same time old agricultural land is becoming infertile, and changes in precipitation aggravate the problem. Cutting the forests causes biodiversity loss and since forests are more effective carbon dioxide sinks than agricultural lands, aggravates climate change.

Apart from cutting rainforests, the most pronounced biodiversity losses are caused by overfishing. Most fisheries at the moment are unsustainable, and aquaculture does not help the situation, as most of the fish feed is made from fish. So, the only change that happens is that for human food less preferred species are caught. An additional problem with aquaculture is the use of antibiotics and pesticides, which affect marine life and be one component of generating antibiotic resistance in the environment.

Besides the decrease of marine biodiversity, especially the large amount of plastic waste in the oceans is an anthropogenic problem. Here an important step forward was taken a day or two ago, whem most countries in the world agreed that plastic waste may not be exported. This will generate national recycling of plastics. Notably, Trump's USA did not sign the agreement. The present government of the USA has been very consequent in the anti-environment actions, opposing any actions which could be seen as trying to improve the state of environment. The US government after Trump will have much to do to reverse the anti-environmental actions of the present government.

If it weren't for plastics, it is likely that there would be other tash all over the place. Different materials, which could be recycled are just thrown away. For example, much of the metals could be reused which would much reduce the need for mining and theeby overuse of world's resources. 

In conclusion, we would need to find ways both to decrease the human population and the amount of energy and resources used by a unit human. Changes in the first pertain especially to developing countries and in the second to inhabitants of traditional industrialized countries. One cannot think in terms "we will do nothing unless the others do their share", because that is a certain way to go to catastroph.

Kommentoi kirjoitusta. Avainsanat: biodiversity, climate change, environmental pollution, economic growth, sustainability

Individual variability is the key for tolerating environmental change

Tiistai 25.12.2018 klo 13:10 - Mikko Nikinmaa

When animal (or plant) populations must face environmental change such as increased themperature, eutrophication etc. the greater the variability bIMG_20170803_0035_NEW.jpgetween organisms, the more likely it is that at least some specimens are able to tolerate the disturbed conditions. Hitherto it has been virtually always been thoght that the only important thing in this regard is genetic variability. However, individual variation is possible also without genetic variation: a single genotype can have quite different phenotypes, which tolerate different conditions. 

In the case that the environment is very labile such phenotypic plasticity - i.e. individual variations in physiological function of one genotype - is better way of tolerating unfavourable environment than having genetically heterogenous populatio with one genotype tolerating that environmental problem. This is because the plasticity of the individuals that tolerate the unfavourable environment is as large as that of the original population. If, however, the tolerance depends on the genotypic variation, it is likely that the overall plasticity of the tolerant genotype is smaller than that of the original, genetically variable population. Genetical variability can be of significant benefit only in cases where the change is to one direction. The possible importance of measures of individual variation in environmental response has recently been discussed in our article (Nikinmaa and Anttila, Aquatic Toxicology, 207, 29-33; open access). Our experimental results on oil-exposed water fleas also indicate that a change in individual variability can occur even when no change is seen in the mean of the measured parameter.

Kommentoi kirjoitusta. Avainsanat: climate change, environmental pollution, phenotypic plasticity

Indirect Effects of Toxicants - Why Contaminants Shown to Be Nontoxic to Animal Cells Can Cause Harm?

Torstai 6.9.2018 klo 11:44

One occasionally sees reports, which clearly show that the concentrations of toxicants in the environment are a million times smaller than those required to cause any effects in animal cells. Yet, other equally carefully done studies show that animals are affected by the concentrations occurring in the environment. This discrepancy often occurs in the case of herbicides. Nowadays they are usually molecules, which do not take part in any metabolic pathways of animal cells.

The simplest explanation for indirect effects in the case of herbicides is that changes in vegetation affect the well-being of animals by affecting the possibilities for hiding, by changing visibility etc. However, occasionally such effects are not adequate to explain  observations.

In such cases it is possible that the toxicant affects the microbiota of animals, and the changes occurring are such that the overall health of the animal is affected. We and all animals have billions of micro-organisms in our body. Some of the organisms have the pathways targeted, e.g., by herbicides. Consequently the microbial communities in animal body will be modified. Research has already indicated that changes in microbiota can influence immunity, digestion, nervous system, affect allergies etc...

An important point to note here is that if only cellular toxicicity is studied, the results indicating that the toxicant is non-toxic to animal cells is correct. It is only, because the microbiota of the animal is affected, and the poorly known signals, required for good animal health, influenced that adverse, indirect effects on animals are seen. This being the case, cell toxicological studies cannot replace studies on intact animals, when trying to uncover the risks of a chemical to the environment.

Kommentoi kirjoitusta. Avainsanat: microbiota, environmental pollution, herbicide

Voluntary actions in conservation - a dream or reality

Torstai 21.6.2018 klo 9:50 - Mikko Nikinmaa

In many cases it is said that environmental actions can be voluntary, that people themselves see if they are required or not. This is wishful thinking. Environmental actions are needed and can be done as long as it is other people doing them, no the persons themselves. Just as an example, a scientific conference of environmental scientists gave a possibility of paying a fee for the carbon footprint caused by travelling to the conference. The fee was at three different levels. Of the environmental scientists only approximately 40 % paid any fee at all, and virtually everyone who paid, paid only the lowest fee, although it was much less than can be estimated to be the environmental cost of travelling. And this was a group of environmental scientists!!!

If the general public is even less concerned about the environment, the noble principle that people voluntarily consider what their actions mean to the environment, and in case they cause deterioration of one aspect, other actions are done to remedy the damage (in another environmental dimension). Consequently, one can probably only get things done by environmental taxes and giving reliefs of them to people, who can demonstrate that they are carrying out environmentally beneficial actions. The taxes are needed, as otherwise people do not take the environment into account. However, probably more can be achieved by having incentives giving a financial benefit for good deeds to the environment.

In view of the above, I bow deep to the individuals who do important deeds to help the environment without expecting anything in return.

Kommentoi kirjoitusta. Avainsanat: environmental pollution, environmental economics, environmenral taxes

Toxicity of Nanoparticles - Hype or Reality

Sunnuntai 8.4.2018 klo 12:27 - Mikko Nikinmaa

During the recent past, the toxicity of nanoparticles (i.e. particles with at least one dimension less than 100 nm) has become a very fashionable field of toxicological studies. There is now ample evidence that the particles can be toxic, if their concentration is high enough. And that is the major problem of most nanotoxicological studies: the nanoparticle levels are often thousands of times higher than what can be expected to occur in the environment. Since one has now clearly shown that nanomaterial can be toxic, it would be high time to study the possible environmental relevance of the toxicity. If there is none, then the studies showing toxicity are irrelevant. This is because one can find toxic amount of any substance. For example, one can demonstrate a lethal dose for water. As Paracelsus said already in 16th century: All substances can be poisonous, the dose makes the difference between remedy and poison.

A significant problem with nanomaterial studies is that the methodology used is suitable especially for dissolved substances in aquatic media, but is not necessarily suitable for the new material. Hitherto, methods, which would be specific and good for nanomaterial research have not been developed. A significant property of nanomaterials is their tendency to aggregate, and the influence of this on the toxic properties is poorly described - it makes definitely a big difference if aggregation occurs before the contact with organisms or only after cellular uptake. One toxic effect of nanomaterials, which is independent of their metal components, is that they cause oxidative stress (and inflammation). This property may get worse with aggregation - we do not know. As the worst possible scenery one can think that nanomaterials cause similar problems in airways as asbestos: this may be fearmongering, but until environmentally relevant nanotoxicology studies are available, the possibility cannot be discounted.

Kommentoi kirjoitusta. Avainsanat: nanotoxicology, ecotoxicology, environmental pollution

Shrinking Ozone Hole - we can remedy environmental problems if we try

Maanantai 6.11.2017 klo 16:04 - Mikko Nikinmaa

An intergovernmental climate meeting just started in Bonn with the main message beforehand delivered: we are not doing enough! The pessimists have got further wind in their sails all through the year from Trump administration saying that they are withdrawing the USA from the Paris agreement.

In view of this, it is important to give hope.And the hope comes from the recent news that the Ozone layer is strongest since 1988. This measured fact shows that if we are united globally, the environmental problems can be solved. Further, the new solutions generate new outcomes.

This positive news creates hope for climate remedy. We can go forward from coal- and oil-dependent world. The new solutions are already present, and generate new paths to those who dare to look forward. Unfortunately, at the moment too many leaders and people of different nations want the past back. However, that is not possible, we must go forward, either by doing what needs to be done or enduring a catastrophe, the outcome of which no-one knows. Which alternative would you choose?

Kommentoi kirjoitusta. Avainsanat: environmental pollution, climate change, global

Plastics removal by micro-organisms

Sunnuntai 24.9.2017 klo 17:50 - Mikko Nikinma

Plastic garbage is a huge problem everywhere in the world. The most visible collections of mainly plastic trash are the Pacific Garbage Gyre and similar smaller ones in the Atlantic and Indian Oceans, but all the aquatic environments have plastic waste and non-visible microplastics. Plastic trash is a highly visible problem also in terrestrial environments.

In the light of the huge plastic pollution problem, two major solutions to alleviate it have been envisioned. The first involves diminishing the use of plastics markedly, collecting plastic trash for reuse, and if the material cannot be reused, burning it. Burning plastic is virtually the same as burning oil, since currently virtually all plastics are made of oil. Thus, burning the plastic trash diminishes the need for oil and thus diminishes its consumption. This way of addressing the plastics problem is tedious, demands a lot of work and time, and requires a change in our daily behaviour. 

The other solution is much simpler. Let's just find a micro-organism, which uses the plastics as an energy source. The evolution of micro-organisms is rapid as a result of their short generation interval. There are both some bacteria which use oil as food and some fungi which decompose plastics. An example of the latter has recently been described in the journal Environmental Pollution (Khan et al. 2017 Environmental Pollution 225, 469-480). Notably, oil-eating bacteria have successfully been used to clean up oil-contaminated soil, so what is simply needed is to have plastic-eating micro-organism placed within plastic trash, and the microbe does the rest. Simple and effective, right?

However, the solution is not so clearcut beneficial. Our world today uses plastics in virtually everything. Already in the beginning of 1972 a book with the name Mutant 59: The Plastic Eaters was written by Kit Pedler and Gerry Davis. In the book, a mutant bacterium was generated (to remove plastic contamination), but it got loose and started eating up, e.g., the plastic covers of electrical wires with the consequence that electrical appliances short-circuited, planes crashed etc. No one can guarantee that the plastic eating micro-organism cannot spread outside of where it is wanted, unless the evolution of organism is directed so that it cannot live anywhere but its wanted target. For example, one could generate the plastic-eating micro-organism so that it is strictly anaerobic, whereby it would die immediately upon contact with air.

However, for developing the plastic-eating anaerobic organism time is needed. Thus, we must primarily use the tedious first alternative.

Kommentoi kirjoitusta. Avainsanat: microplastics, garbage gyres, environmental pollution, plastic waste

Recycle

Maanantai 21.8.2017 klo 14:00 - Mikko Nikinmaa

When I was a child all the cloth, paper and glass were recycled. From then on one changed from reuse culture to culture wasting materials. As a result, we are using in half a year what the earth can tolerate for one year. Environmentally thinking, our wasteful ways should be over.

Wasting materials has been the cheap alternative largely because the long-term damage to and costs incurred by the environment have not been part of any economic calculations. For example, the gross national product does not take into account, e.g., the water pollution caused by industrial production. For this reason, paper and pulp mill directors said in 1970s that: "One cannot build effective wastewater treatment plants, since our products will then become so expensive that they cannot be sold". If environmental damage had been part of economic calculations, that would not have been the case.

But from wasting to recycling. There are already examples, which show that recycling can function. In Finland we have returnable bottles and aluminum cans. As the result, at least 95 % of drinking bottles are returned. Glass bottles can then be washed and refilled. Aluminum cans are pressed, and new cans can be produced. Plastic bottles can also be washed and refilled. Most paper is reused. One is paying recycling fee when buying tyres - the old tyres are then used, e.g. on road surfaces.

For some reason the recycling of cloth has been all but forgotten. This is surprising, as the treatment of cloth so that fibres could be reused is not more expensive than making cloth from native cotton plants, and would be more environmentally friendly. It would just require a change of attitude. Also, reusing all the metals would markedly diminish the need for mining and associated activities. Again, it would not be more expensive, but would need new way of thinking.

All in all, in much of advocating recycling, we are not talking about things becoming more expensive, but about a change in attitude. Recycling needs to be done not because we are poor but because it helps to give our children a habitable planet.

Kommentoi kirjoitusta. Avainsanat: mining, gross national product, environmental pollution, waste