APLICACIONES DE LAS BACTERIAS LÁCTICAS

A weakness of a large part of humanity’s perception about itself is that it is above nature and separate from it, this is not so. People are an integral part of Nature and intimately interwoven with each another as the cycles of water, air and nutrients flowing through us confirm. The active ingredient of the contraceptive pill, ethynyl-oestradiol (EE2) is a chemical which is sub- sequently excreted and eventually escapes through the treatment of sewage at waste-water management plants and finds its way into the environment, lakes and rivers. Today many of Europe’s rivers are polluted with this particular endocrine-disrupting chemical EE2 along with others (Gilbert, 2012).

Endocrine-disrupting chemicals may be simply de- fined as chemicals or chemical compounds which inter- fere with the functioning of the body’s normal hormone activities. Endocrine-disrupting chemicals (EDCs) are found in various man-made products including: pes- ticides, metals, additives or contaminants in food and personal care products (Bergman et al, 2014). The US National Institute of Environmental Health Sciences writes on its web page that “A wide range of substanc-

es, both natural and man-made, are thought to cause endocrine disruption, including pharmaceuticals, dioxin and dioxin-like compounds, polychlorinated biphenyls, DDT and other pesticides, and plasticizers such as bisphe- nol-A. Endocrine disruptors may be found in many every- day products – including plastic bottles, metal food cans, detergents, flame retardants, food, toys, cosmetics, and pesticides” (NIEHS, 2014). Not very cheering.

Through the process of evolution, various chemi- cals have evolved to perform physiological functions in animal bodies and due to their success in performing signaling functions hormones have not significantly changed throughout evolution as much as animals’ anatomies have done. Consequently, while ethynyl-oes- tradiol (EE2) not only has a contraceptive effect in hu- mans by disrupting the female body’s normal repro- ductive cycle it also disturbs the sexual physiology of other organisms including fishes. The EE2 escaping into

10.10 Freshwaters

waterways from sewage treatment plants has had the effect that “Many of Europe’s rivers are home to male fish

that are ‘intersex’ and so display female sexual character- istics, including female reproductive anatomy. Some males also produce vitellogenin, a protein normally found in eggs that can be induced in males by hormone exposure. In one of the largest studies of the problem, the UK government’s Environment Agency found in 2004 that 86% of male fish sampled at 51 sites around the country were intersex … The feminization affects fish health and lowers the sperm count in males, raising the risk of a population crash” (Gilbert,

2012).

Another chemical, diclofenac, which is used as an anti-infammatory drug is renown for having decimated the vulture populations in Asia, and is also affecting Eu- ropean fishes by disrupting cell function in their livers, kidneys and gills (Gilbert, 2012).

In 2012 a landmark regulation was proposed by the EU aimed at cleaning Europe’s waterways of pollution by pharmaceuticals and limiting the concentrations of these widely used drugs. Once again this has resulted in intense lobbying by two big stakeholders, in this case the water and pharmaceutical industries “which say that

the science is uncertain [a standard corporate rebuttal] and the costs too high. European Union (EU) member states, alarmed by cost estimates of tens of bil¬lions of euros, seem to agree. Researchers and environmentalists question those estimates, and argue that the proposal should be judged principally on what they say is strong scientific evidence, rather than on financial concerns” (Gil-

bert, 2012). The result of the vote on 28 November 2012, by the EU parliament was that due to the unacceptable costs of “end-of-pipe” purification, action would be de- layed on the issue for a decade (Carr & Moroz, 2012).

“Environmental scientists say that the case for action will only get stronger. Fish populations may be stable now, but a study of fathead min¬nows (Pimephales promelas) in an experimen¬tal lake in Canada has shown that exposure to high levels of EE2 triggered a population crash. And re- searchers think that the EU is missing a chance to set a global precedent. “It’s a test case for regulating pharma- ceuticals in the water,” says Jobling. “If they don’t regulate on EE2, they won’t regulate anything” (Gilbert, 2012).

A year later in July 2013 the ClientEarth group of lawyers who work to protect the environment “released

a report [Hiester, et al. 2013] indicating that manufacturers are ignoring, misrepresenting or disregarding the potential of certain chemicals to disrupt hormonal systems (EDCs)…

The five substances investigated in the report are diethyl phthalate, bisphenol-A, tetrabromobisphenol A, triclosan and octyl-methoxycinnamate” (Leigh, 2013).

Once again we see how politics, lobbied by indus- try in the end does industry’s bidding and in this case, demonstrates how prepared it is to let big industry pol- lute the environment in order to protect its profits.

10.10.2 Eutrophication

A larger and significant political issue envelopes sus- tainability which is the de-funding of science by poli- ticians because of the truths it reveals which demand political action; actions frequently inconsistent with party policies and corporate enterprise. George Bush was heavily criticized by the US scientific establish- ment during his presidency for cutting the funding to science. Currently, the Australian prime minister, Tony Abbott is defunding Australian climate science and im- plementing a range of unsustainable policies. In Cana- da the defunding of science was to have included cuts to a series of freshwater lakes, known as the Canadian Experimental Lakes Area (ELA) consisting of 56 small lakes which “were set aside for experimental studies of the

causes and control of eutrophication and other types of water pollution” (Vallentyne, 2000). Since the 1970s the

ELA has provided invaluable scientific evidence of how pollution causes eutrophication. However, following a strong protest campaign, the politicians repealed their decision to close the ELA and happily “on April 1, 2014,

the International Institute for Sustainable Development, the Government of Ontario and the Government of Can- ada signed three agreements to ensure the long-term op- eration of the Experimental Lakes Area (ELA), a world-re- nowned freshwater science research facility in northwestern Ontario, Canada” (http://www.iisd.org/ela/).

In the -60s algal blooms were plaguing Lake Eerie and the Canadian government set up the Freshwater Institute to investigate the problem. The new director, Waldo Johnson, had the idea to conduct research by using a series of small lakes in a remote area of Can- ada, near Winnipeg for experiments. Once the lakes had been selected the experiments went ahead and the lakes were used in the same way that medical research- ers use white mice!. “ELA’s original mission was to exam-

ine the problem of eutrophication. The pressing question in the late 1960s was which nutrient triggers excessive algal growth. Studies in small tanks done elsewhere had yielded conflicting data. Some scientists thought the culprit was

10.10 Freshwaters

phosphorus, principally in detergents and sewage; others thought it might be nitrogen from fertilizer and sewage, or carbon, or perhaps even trace metals. In a now-famous experiment ([Schindler, 1974] Science, 24 May 1974, p. 89), the team divided Lake 226 with a plastic curtain and added phosphorus to one half. When it turned a distinctive murky green, they had their answer. It was an aerial photograph from this experiment that largely persuaded policymakers to phase out phosphorus from detergents. “I think that’s the single most powerful image in the history of limnology,” Elser says” one of the ELA scientists (Stokstad, 2008).

Today the use of phosphorus and nitrogen fertiliz- ers by the agro-industry has caused serious problems throughout the world due to their repeated, heavy and extensive application on farmland. Rains wash the fer- tilizers off the land into lakes and rivers and eventually these chemicals reach the sea. The excess nitrogen en- riches the water causing algal blooms and an increase of the plant biomass. Subsequently, as the plankton and plants die off and rot they reduce and exhaust the oxygen in the water killing off nearly all the other or- ganisms. This causes deoxgenated dead zones in both bodies of fresh- and seawater; this process is known as eutrophication (Harper, 1992). Eutrophication can also be caused by the release of sewage into water so that it is over-enriched.

Although, we are concerned with freshwater pollu- tion and the eutrophication of ponds, lakes and rivers – but rivers also flow to the coast transporting our pol- lution to the seas. Our world is intimately interlinked in many ways and eutrophication also occurs very seri- ously around our coasts due to the runoff of fertilizers and sewage. There are now extensive ‘dead’ areas along the coasts of all continents close to city seaboards. “The

Gulf of Mexico’s dead zone, averaging more than 17,000 square kilometers in recent years, was forecast to reach record dimensions this year before a tropical storm stirred the waters” (Elser & Bennett, 2011). In 2008 it was re-

ported that “In many coastal regions of the world during

the past 60 years, the concentration of dissolved oxygen has declined to levels anathema to life and the number and extent of listed hypoxic [= absent or reduced oxygen

content] areas has increased from 46 in 1995 to more than

400. Loss of dissolved oxygen is linked to the release of nu- trients when organic waste or fertilizer runs off into river outflows. Hypoxia poses a grave threat to the viability of coastal marine and estuarine ecosystems and can quickly lead to the elimination of the sea bed organisms and fish.

Diaz and Rosenberg … review how the issue of dissolved oxygen may become the most important factor controlling man’s use of the sea” (Hurtley, 2008; Diaz and Rosen-

berg, 2008).

The issue of eutrophication is a deeply intercon- nected sustainability issue, because it is intimately associated with water which cycles through the eco- sphere. Legislation forced the removal of phosphates from detergents to counter eutrophication (Stokstad, 2008), however, the situation with agriculture or rath- er the agro-industry remains. Does the world need to use so much chemical fertilizer which in the last fifty years has more than quadrupled to a 142 million tons per year (Pretty, 2007)? Scientists have already shown that simply adding more fertilizer year after year does not increase soil fertility. “All else being equal, the high-

est efficiency of nitrogen fertilizer is achieved with the first increments of added nitrogen; efficiency declines at higher levels of addition. Today, only 30–50% of applied nitrogen fertilizer and ~45% of phosphorus fertilizer is taken up by crops. A significant amount of the applied nitrogen and a smaller portion of the applied phosphorus is lost from agricultural fields … Such non-point nutrient losses harm off-site ecosystems, water quality and aquatic ecosystems, and contribute to changes in atmospheric composition. Ni- trogen loading to estuaries and coastal waters and phos- phorus loading to lakes, rivers and streams are responsible for over-enrichment, eutrophication and low-oxygen con- ditions that endanger fisheries” (Tilman, et al. 2002). On

balance the stakeholder who benefits most from the greater use of fertilizer is neither the hungry nor the farmers but the chemical industry giants. It is an ex- ample of diminishing returns; the more fertilizer used then the less the increase of productivity and the great- er the variety of externalities but more profits for the agro-chemical industry. “More and more evidence shows

that organic farming, even on a large scale, can ensure roughly the same amount of nutrients in crop production as does conventional agriculture using chemical fertiliz- ers” (Wijkman & Rockstöm, 2012). It is increasingly clear

that the agro-chemical industry is superfluous except to itself because organic farming can achieve similar productivity without chemicals (Wijkman & Rockström, 2012).

If we just consider the fertilizer element phospho- rus, which is essential for all life, it is forecast that the

“easily mineable deposits of phosphate rock are limited”