By Alessandro Graziadei for our partner Unimondo
The world is still grappling with Covid 19 and its new variants, most recently Omicron BA.5. Meanwhile, although mortality rates from Covid in Europe ‘have remained stable over the past five weeks’, epidemiological models ‘indicate that both case notification rates and mortality rates will increase’. This is what the ECDC writes in a note accompanying the ‘Preliminary public health considerations for Covid-19 vaccination strategies in the second half of 2022′ published on 18 July. Looking ahead to the autumn, the ECDC indicates the urgency of establishing robust and integrated surveillance systems for the pandemic and for respiratory viruses in general. This is an emergency that seems never-ending: medical advances and media analysis are still focusing almost exclusively on the immediate priorities, i.e., saving people and economies from this coronavirus. However, our response to this emergency should begin by addressing the causes of this pandemic, which cannot be dismissed with fatalism. Let us try to retrace and analyse some of the critical environmental issues that Covid-19 has brought to light in recent years.
It was not only predictable, it was foreseen
This pandemic, many experts say, was neither unforeseen nor inevitable. As Andrew Cunningham, Deputy Director of the Zoological Society of London, reminded us back in 2020, ‘The emergence and spread of Covid-19 was not only foreseeable, it was predicted there would be a viral outbreak from wildlife that would be a threat to public health’. A few examples: the SARS virus that caused more than 800 deaths and cost more than $80 billion globally in 2002-2003 should have given us a clear clue: it emerged from bats, spread to palm owls, and then infected people in live animal markets in southern China.
In 2007, the study ‘Severe Acute Respiratory Syndrome Coronavirus as an Agent of Emerging and Re-emerging Infection’, published in Clinical Microbiology Reviews by a team of scientists from the University of Hong Kong reminded us that ‘The presence of a large reservoir of Sars-CoV-like viruses in horseshoe bats, coupled with the culture of exotic mammal consumption in southern China, is a ticking time bomb’. In 2012, in the fictional essay ‘Spillover’, writer and popularizer of science David Quammen, combining literary history and scientific analysis of major epidemics, wondered whether the next one might not pop up from ‘a city market in southern China’. In 2015, Bill Gates’ famous Ted Talk made headlines as he recalled how ‘In 2014, the world averted a horrific global Ebola epidemic, thanks to thousands of selfless health workers and, frankly, thanks to a lot of luck. In hindsight, we know we should have done better.” A year later, in 2016 the United Nations environment programme (UNEP) study ‘Emerging issues of environmental concern‘ reminded us that ‘Zoonoses [i.e. diseases transmitted from animals to humans] are now a real threat to economic development, animal welfare, human health and the integrity of ecosystems’. Why? Because, not only in China, the trade and trafficking of wildlife or parts thereof brings different species into close contact, facilitates genetic recombination between viruses and with it ‘spillover’, i.e. the ability to infect new species, including humans. This is why Quammen, in 2020 in the New York Times, recalled how these viruses are now nature’s inevitable response to a ‘pandemic environment’ due to man’s assault on natural resources, to the extent that ‘by the time you’re done worrying about this epidemic, you should already be ready to worry about the next one’.
Better safe than sorry: Prevention should come first
According to the scientific community, it is almost always human behaviour that causes epidemics and we should expect more and more of these in the future if we do not change certain eating habits. For Professor Cunningham, for example, ‘Markets where live wild animals are slaughtered all over the world are the most obvious example. […] Animals are transported over great distances and are crammed together in cages. They are stressed, immunosuppressed and expel whatever pathogens they have inside them. A large number of people in a market and in close contact with the body fluids of these animals creates the emergence [of disease]. If you want a scenario to maximise the chances of transmission, you couldn’t think of a better way to do it’.
Compared to the current Covid-19, other wildlife diseases passed to humans in the same way have had much higher mortality rates in people, such as 50% for Ebola and 60% to 75% for the Nipah virus. Apparently, therefore, if there was ‘good’ in recent decades it was only because ‘few’ and ‘far between’ died from very dangerous diseases such as Sars, Ebola, avian influenza, Rift Valley fever, Nipah virus, West Nile virus or Zika virus, all zoonoses that remained largely confined to developing countries. Similarly for UNEP Director Inger Andersen, the Covid-19 outbreak is a clear warning: ‘Very dangerous diseases exist in wildlife and human civilisation is playing with fire, as it is almost always human behaviour that causes zoonoses to spread to humans’. While the scientific world has been arguing for years that climate change, deforestation, loss of biodiversity, intensive farming and livestock breeding, population growth and building expansion right into protected areas, are all bringing us more and more into contact with debilitated and suffering wildlife, the most pressing problem remains that of legal and illegal urban live animal markets, which become the ideal place where infectious diseases can spread. For WWF, ‘There is evidence that contact with wild species such as bats, palm owls, monkeys and other animals (mainly birds and mammals) can lead to and contribute to the spread of serious zoonoses. It is no coincidence that recurrent outbreaks of Ebola epidemics are often linked to the consumption of contaminated monkey meat’.
For the NGO, ‘Every year, 28,000 monkeys are hunted and consumed in Peru alone. In Indonesia, in addition to monkeys and other wild mammals, 25 tonnes of turtles are caught and exported’, while throughout Africa ‘bushmeat’ is widespread in urban and affluent areas, where wild meat is preferred for its taste. According to the United Nations Office on Drugs and Crime, we are talking about a market that globally leads to the loss of biodiversity, increases the risk of pandemics, but generates a global turnover of between $7 and $23 billion per year. The Covid-19 crisis may offer an opportunity for change.
The ecology of the disease
The study ‘The Coevolution Effect as a Driver of Spillover’, published in 2019 in Trends in Parasitology by a team of researchers at Auburn University, has formulated an interesting new hypothesis that could provide the basis for new scientific studies examining the links between habitat loss and the global emergence caused by zoonotic infectious diseases. For lead researcher Sarah Zohdy, of the School of Forestry and Wildlife Sciences and the College of Veterinary Medicine at Auburn, it is possible to argue that globally, “Habitat loss is associated with emerging infectious diseases (EIDs) that spread from wildlife to humans, such as Ebola, West Nile virus, SARS, Marburg virus and others. To explain the mechanisms behind this association, the Auburn team studied the co-evolutionary effect, which is rooted in ecology and evolutionary biology.
The team integrated ideas from multiple aspects of biology, including disease ecology, evolutionary biology and land genetics, to develop a new hypothesis on why diseases are more likely to spread from wildlife to humans in cleared habitats. This approach aimed at analysing the ‘ecology of disease’ is mainly based on a hypothesis known as the dilution effect. For Zohdy, ‘It is essentially the idea that biodiversity conservation can protect humans from emerging infectious diseases. The dilution effect highlights the fundamental role that wildlife conservation can play in protecting human health’. Following this hypothesis, the scientists hypothesised that while humans alter the territory with habitat loss, ‘forest fragments act as islands and the wildlife and disease-causing microbes living within them undergo rapid diversification. In a fragmented territory, we would therefore see an increase in the diversity of disease-causing microbes, ‘increasing the likelihood of one of these microbes reaching human populations, triggering outbreaks’. The study, therefore, introduces an evolutionary mechanism to explain the association between habitat fragmentation and the spread of disease in human populations, a finding that could lead to a significant change in the way the origins of these diseases are perceived.
A ‘sustainable’ Covid-19?
During the lockdown months, air traffic was reduced worldwide and almost all people stayed at home, working remotely. As a consequence of the shutdown of major industries, and the limited use of cars, emissions of NO2 and, to a lesser extent, PM2.5 in Europe fell dramatically, as satellite images also showed. For researchers at the Italian National Research Council (CNR), however, the ‘benefits’ brought by the lockdowns on pollution have been ephemeral and short-lived, and not all of them have proved sustainable and useful for a change of course in the development of climate change.
Although emissions of some greenhouse gases have decreased as a result of the pandemic containment measures, this reduction has had little or no effect on the total concentrations of pollutants accumulated in the atmosphere over decades. “In fact,” explained Francesca Gorini and Fabrizio Bianchi of the CNR Institute of Clinical Physiology in Pisa, “it has long been well documented that for a significant and permanent decrease there would have to be a long-term structural change in national economies, a result that can only be achieved through the ratification of the environmental commitments made (COP21). Moreover, the decrease in pollutant emissions observed in some countries was only temporary, so the indicators available so far do not allow for optimism about changes in the world economic system, which is still projected towards a return to its original state. It is important to remember that while the indirect effects of the new coronavirus on the environment include mainly the reduction of air and noise pollution in concentrations that will soon rise again, there are also many negative effects related to the increase in household and medical waste. The increase in online shopping with home delivery, for example, has generated a large increase in organic and inorganic waste, which has added to the increase in medical waste, starting with personal protective equipment (PPE). ‘Suffice it to say,’ the researchers explained, ‘that hospitals in Wuhan produced an average of 240 tonnes of medical waste per day during the outbreak, compared to their previous average of less than 50 tonnes.
In other countries, such as the United States, there was a large increase in waste from personal protective equipment such as masks and gloves, while waste recycling programmes in some American cities were discontinued due to concerns about the risk of spreading Covid-19 in recycling centres’. In Italy, things were no better. Medical waste such as masks, gloves, used or expired medicines, which can easily be mixed with household waste, should be treated as hazardous waste and disposed of separately by specialised municipal operators. They should indeed.
Finally, despite the seriousness of the pandemic, there is a glaring asymmetry between the just attention to the health consequences of the pandemic and the unjust inattention to the health damage of pollution. “The numbers speak for themselves: nine out of ten people in the world today breathe polluted air that kills 4.2 million people every year, while 412,000 premature deaths have been estimated across Europe, including 374,000 in the 28 EU countries, from exposure to PM2.5. Although the impact estimates are for 2016 data and several developed countries are seeing a gradual improvement, based on the most recent environmental data the global situation is not expected to change radically in the coming years. In Italy, for example, a significant improvement is expected, but we are unlikely to drop below 30,000 deaths from pollution each year. For the time being, the issue of pollution and health is at the centre of the reflection and action mainly of NGOs, associations and committees engaged at various levels on major environmental issues, and while we are witnessing a progressive consolidation of the link between science and citizens, the link between science and politics still seems a mirage in this field.
Cover image: Brian McGowan, 2020