Articolo

The difficult coexistence between human activity and the environment is not a recent issue. It began when agriculture was introduced into Eurasia about 12,000 years ago. William Ruddiman, famous American climatologist, recently suggested that deforestation and the extensive establishment of fields and paddyfields had relevantly affected the earth’s climate during the past 5000 years1. However, only in the industrial era has it triggered an uncontrollable mechanism: the discharge of pollutants and carbon dioxide into the atmosphere, which phenomenon is decidedly beyond the scales of natural fluctuations, and which sets the premise for future disastrous climatic changes1. Environmental degradation kept up with economic development in the 19th and 20th centuries, though the knowledge and awareness of environmental damage related to industrial activities is a phenomenon that has taken place in the last decades of 1900. Scientific attention targeted at environmental degradation can be gauged by studying the number of publications in international literature. In Medlars database, National Library of Medicine, USA2, articles containing the key word “Environmental Pollution” numbered about ten thousand in the five-year period 1976-80, and this number has increased in just one year. It is interesting to notice that only an average 2% of these publications is from Italy.
Five decades of culture and scientific research on environmental issues are quite a long time and they enable to check the reliability of certain “historical” analyses. For example catastrophic forecasts centred on demographic explosion were in fashion in the ‘70s.
Paul Ehrlich3, a famous Californian biologist, wrote in 1971 that the exponential population increase would have shortly led to inadequate food resources throughout the planet. Quite the contrary. This did not take place; beside one of the emerging problems is rather agricultural and industrial overproduction.
And if current demographic dynamics remain unvaried, the international population will settle around a value of 8-9 billion at the end of the 21st century, to then begin a descent even in less industrialized nations, as occurred in industrialized nations in 19004. Another prophet of environmentalism, Barry Commoner, former professor at the University of St. Louis, USA, wrote in The Closing Circle5 in 1971: “the current ecological stress is so violent as to make the earth uninhabitable for man”.

This catastrophic forecast has proved untrue so far and the estimate mean life span of populations in industrialized nations has considerably increased in the past decades and will probably continue to do so throughout the 21st century6. This phenomenon concerns the world’s poor countries too, with some exceptions mainly due to political and economic conditions
But if some harbingers of doom have proved unreliable, it would be entirely unjustified to go to the other extreme, in other words that problems concerning environmental pollution are irrelevant or that a quick solution is being found for all of them. The list of the most urgent environmental issues is long, complicated and controversial. My professional orientation will no doubt play its part in making me suggest certain issues instead of others. That being stated I believe that the main unsolved international problem concerns Persistent Organic Pollutants (POP).
I would like to begin this analysis from an “ancient” chemical substance, which many believe has long since disappeared. Those who were born towards the end of World War 2 recall DDT as a beneficial insecticide that was brought to Italy by the American troops and which made entire costal regions inhabitable, helping our population to be free of flies, mosquitoes and the last traces of malaria. Unfortunately a few decades later it appeared clear to all that DDT was neither beneficial nor harmless, because it tended to bioaccumulate, causing irreversible damage to birds, fish and mammals. The last and final unacceptable toxic effect was DDT’s capacity to cause tumours in animals for experimentation and probably in man too8; this point played an essential role when DDT was first banned in the US and then in other industrialized nations. The fact that the production of DDT was not stopped is not common knowledge; its production was moved to poor countries, following a behavioural pattern typical of chemical industries. And as the world is not so large after all, DDT, a remarkably stable substance, first evaporates in tropical countries. Air currents carry it northwards, where it condenses, precipitates and pollutes the temperate and cold zone of the earth. This phenomenon could be defined “planetary distillation”. That which was dumped in the poor man’s courtyard returns by the rich man’s window.
There are many examples of these global exchanges of persistent chemical substances. In the case of DDT, contamination levels in tree cortices in countries like Sweden and Canada, which have long since stopped producing it, are higher than in Mexico and Brazil, where DDT is still extensively used9. In 2001 ninety nations signed an international treatise to ban 12 of the worst persistent toxic substances, including DDT. However some nations still use chlorinated pesticides, which are cheap and allow applications that are more distanced in time. DDT is only one of the stable contaminants (POP) that accumulate in the environment because few living organisms are able to metabolize them. A recent article published in Science revealed that 10 types of POP are present in relevant concentrations in farmed salmon. Figure 2

POP concentrations in farmed salmon are so high (especially in the European salmon that comes from polluted North Sea regions) that EPA (Environmental Protection Agency, USA) recommendations advice the consumption of a portion of salmon less than once a month.
POP, highly toxic substances that are now widespread, are also polychlorinated dioxins. Dioxin concentration in marketed salmon is 2 pg/g moist weight10, which is about 4-5 times higher than the remarkable levels found in beef from Northern Europe. It does not come as a surprise at this stage that polychlorinated dioxins are even present in relatively high concentrations (tens of picograms/g of fat) in the milk of north European women; the highest levels can be found in samples taken in Belgium11. Dioxin levels in mother’s milk in Italy, if ever measured by anyone, have never been communicated to the European Environmental Agency.
Similar considerations also apply to polychlorinated biphenyls (PCB), widely used in chemical industries and power plants in the ‘50s and later banned due to their toxicity and persistence in the environment. They are still present in great part of the world and reach high concentrations in fish10. Analytical data has long since shown serious environmental pollution, in particular in North Sea marine sediments, resulting from PCBs, just like heavy metals. If we study European contamination maps, the Mediterranean area would seem a happy isle11. In practice just a few analyses suffice to recognize areas that are heavily contaminated by PCB in our country too (like the Venetian lagoon). Bioaccumulation of Estrogen Disrupting Chemicals (EDC), which seriously alter sexual differentiation processes, is another issue of great concern. The altered sexual development of turtles, crocodiles and fish associated to the presence of Estrogen Disrupting Chemicals has been reported in many parts of the world12-14. It was recently reported that over 1% of polar bears in the arctic Norwegian island of Svarbard are now hermaphrodites14 and a special department dedicated to these issues has been formed in Scandinavian scientific societies.
One of the environmental issues loaded with disastrous implications for the future of human societies we wish to recall is the appearance of microorganisms resistant to antibiotics, the result of medical practice, which is at times questionable, and especially of the excessive and almost always unjustified use of antibiotics in industrial zootechnics. The combination of these two factors is leading to the loss of sensitivity to antibiotics found in the most relevant pathogens for humans figure 3, reported by publications in the “Alexander Project”19, an international project dedicated to the study of antibiotic-resistance (Alexander the Great died of pneumonia in Babylon in 323 B.C. ). Though in recent years the situation seems to have partly stabilized in the southern hemisphere, the reduction of ozone concentrations in the stratosphere, which causes skin cancer and eye degeneration and even an increase in leukaemia, as suggested by a recent Swedish study20, is still worthy of notice.
Concluding I shall mention two pollution issues typical of all industrialized societies and which affect the cities of the world, though industrialized nations have left the most dramatic situations of air pollution behind (when we used coal and wood to heat houses and cook, and large factories were located in city centres). To make a few examples I shall analyse the concentration of certain air pollutants in the city of Florence, which is more or less similar to that of major cities in the north and centre of Italy. Figure 4

The concentration in city air of polynuclear aromatic hydrocarbons (PAH), and of benzopyrene in particular, a powerful carcinogenic substance, has diminished in recent years21, but it is still high and the situation can improve with difficulty without structural interventions on traffic and without the introduction of revolutionary technologies for transport. Photochemical smog produces measurable damage to respiratory mucous tissue in summer and its composition is still mainly unknown, though we now know with certainty that the primary cause that forms a reactive mixture of oxidizing substances in the air are vehicles. Concentrations of carcinogenic pollutants, like benzene and aromatic amines, in city air are certainly not negligible and their chronic effects are still ill defined. The levels of aromatic amines in the air are in fact two or three times higher in medium to large built-up areas (like Florence and Prato), compared to country areas like Sticciano, in Maremma. figure 5
The levels of these pollutants in the air of cities located near old and polluting industrial plants, like Brin disi, are ten times higher than levels measured in rural areas and are similar to levels present in closed environments contaminated with cigarette smoke. Most Italian rivers, where we could bath, wash clothes and go fishing as children are now polluted and malodorous. According to a report of the Ministry of the Environment the situation of major streams in Tuscany, considered one of the gardens of the world and yearly visited by millions of tourists, is for example unsatisfactory from a chemical and bacteriological pollution viewpoint.
figure 6
The choice of certain typical problems concerning environmental pollution is certainly influenced by the culture and personal tastes of the author. But it would be wrong to bring this review to a close without mentioning pesticides. In fact “biological” or “integrated” agriculture (which makes a targeted and controlled use of pesticides) is a fast growing sector in European economy. However the consumption of pesticides in Italy gives no sign of diminishing. figure 7

In fact the total amount of pesticides marketed in Italy fluctuates around 170,000 tons/year, one of the highest rates of consumption in the European community (15 kg per cultivated hectare as per an estimate made in 199223, equivalent to about 300 grams per year per person). How can the sudden interest in “biological” products shown by certain groups of consumers astonish us? Most of this data is known to public opinion and to politicians. Laws and regulations have been passed at an EU level to control and reduce environmental pollution. The so-called 6th amendment, approved in 1979, sanctioned the principle by which newly produced industrial chemical substances must first be tested to ascertain their toxicity and biocompatibility. Environmentalists welcomed these laws as the dawn of a new era and the solution to the relentless conflict between production and respect for the environment. However things have taken another turn. Twenty-five years later24 only a few dozen of the one hundred thousand chemical substances present in the market have been included in the priority list to be examined by European Commissions for Toxicology and evaluations of their toxicological impact were completed only for just over ten substances. Muddled procedures and, in some cases, the decided though unconfessed opposition of certain countries have made the 6th amendment a practically ineffective provision. A new procedure backed by the European Minister for the Environment is now being discussed. It proposes a sort of self-certification of biocompatibility issued by manufacturing firms; we presume it will be quite realistic and easy to apply to become effective. We shall see… The environmental issues discussed are complex and some place worrying unknown factors for the future. The control and reduction of environmental pollution however require relevant investments and a firm political decision (a factor that seems problematic right now due to the many urgent issues of other nature). It is with some anxiety that we witness public opinion focus on highly specialized environmental issues, which are at times questionable.
I refer for example to electromagnetic or “electrosmog” (a popular Italian neologism) pollution. The biological effects of electromagnetic fields have long been studied internationally, mainly with uncertain results. Exemplary epidemiological studies concluded with negative results25; others with uncertain results and yet others with the causal association of exposure to electromagnetic fields and certain diseases like leukaemia26. The relevance of electromagnetic fields in inducing leukaemia appears quite limited on the whole, considering the presence of benzene, a well-known powerful cause of leukaemia, in city air and in cigarette smoke27. Concerning the high frequencies of electromagnetic fields, Italian density of mobile phones is one of the highest in the world, besides Italy is also the nation that most fears the harmful effects of electrosmog, when the number of new stores specialized in telephony is undergoing an exponential growth. It is hence hard to consider environmental exposure to electromagnetic fields a national emergency.

Environmentalist movements, not only Italian ones this time, are also concerned that genetic engineering can lead to the creation of biological Frankensteins with unpredictable and terrifying environmental consequences. These fears decidedly neglect the fact that genetic engineering has long since established itself silently among us. The pharmaceutical industry has synthesized active substances by transferring mammal genes to bacteria for decades. The transfer of insulin genes to E. coli, which freed us from our dependence on porcine insulin, was an early success, though it turned bacteria into a pig, as Barry Commoner, one of the fathers of ecology, jokingly said. The list of biotechnologically produced drugs now comprises hundreds of substances (tab. 1), some with life-saving properties.
Table 1. Drugs currently in use or under experimentation, produced by means of genetic engineering. No environmentalist of sound mind would dream of avoiding the use of insulin or recombinant erythropoietin for a son suffering from diabetes or leukaemia. The synthesis of new drugs with biotechnological methods is no doubt another matter to the introduction in the environment of species containing unknown biological and ecological properties. There is a possibility that new species may cause unforeseen changes in environmental balances. The past counts ecological calamities when vegetable and animal species were moved from one habitat to another. We recall the introduction of 10 rabbits in a farm run by British settlers in 1859; it resulted in a real rabbit invasion of Australia. These rabbits are now millions and the damage they cause amounts to about 370 million dollars a year, besides the incalculable damage wrought to the biodiversity of an entire continent. We can also recall the introduction of water hyacinths in Egypt at the close of the last century. African streams were infested with a plant of Amazonian origin that produced magnificent flowers, but prevented navigation, seriously damaged fishing and increased the risk of parasitoses. Some believe that OGMs are more dangerous than rabbits and water hyacinths. However the Genie is now out of the lamp and many OGMs have spread in the environment, i.e. corn in Mexico or cotton modified with the Bacillus thuringiensis’ toxin, as recently documented in India. Many members of the scientific community are convinced that crusades against genetic engineering are best avoided and that an empirical attitude should be adopted to scientifically examine each case, evaluating the possible environmental benefits and disadvantages on the basis of controlled experimentations. But the logic behind certain genetic engineering projects is hard to understand, i.e. the manipulation of gene resistance to weedkillers in practice still leads agriculture to resort to polluting chemical substances. But the possibilities are rather promising. Transgenic tomatoes resistant to high concentrations of sodium chloride would enable extensive cultivations in regions made sterile by salinization. Essential provitamins, like carotenoids, could be introduced into some varieties of rice, thus solving nutritional deficiencies in billions of individuals and removing the most relevant cause of blindness in the third world. Most researchers are convinced that experimentation with genetically modified organisms can present environmental risks, but it also holds great potential. Instead there prevails a negative attitude towards genetic engineering, even for experimental use, in many sectors of public opinion. The press often exhort us to avoid food containing OGM for disease prevention, though scientific literature has no reliable experimental or clinical study that associates the consumption of food containing OGM with pathological effects on man or in animals for experimental use.

It is essential to count on a solid scientific community and on high standards of research and scientific information in such a situation packed with complex environmental issues, some even marked by worrying implications for the future of the world. These standards can be found in many industrialized nations, but absolutely not in Italy, which has become one of the taillights of European research due to deliberate neglect on the part of its governments, excluding none. Italian toxicological and environmental research is in a sorry state, to say the least. The Ministry of the Environment has been incapable of promoting research programmes and Regional Agencies have a hard time keeping up with emergencies; besides ARPA technicians, save rare exceptions, do not publish their data on international reviews. The combination of all these factors result in the often incomplete reports of poor scientific standing produced by the Ministry of the Environment, the only source of information on the nation’s environmental conditions. We are aware that the progress of science alone does not solve all problems.