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.
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.
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.
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?
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.
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.