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Climate change will harm our health

Asthma, allergies, bronchitis, malnutrition ... climate change will have remarkable effects on the health of everyone. The journal The Lancet has declared climate change as the major health challenge of the XXI century. Respiratory diseases and the health of children are two of the main areas of concern.

ÀNNIA MONREAL | NOVEMBER 25TH, 2010

Between 8% and 14% of Spanish children and adolescents suffer from asthma, a chronic inflammatory disease that causes the obstruction of the bronchi and makes breathing difficult, according to the Roger Torné Foundation. Asthma patients are growing in number, and it is a condition in which environmental factors are playing a more prominent role due to the atmospheric changes caused by global warming. This is just one example of the many consequences to human health posed by climate change.

"Children are more vulnerable because they are more exposed to pollutants due to their weight and size. Furthermore, their body and immune systems are still developing. And finally, what takes place in the early stages of life affects you the rest of your life and may be decisive in your health,” said Jordi Sunyer, researcher and co-director of the Center for Research in Environmental Epidemiology (CREAL). The discovery of the relationship between respiratory diseases and climate change is not new, but scientists insist on the severity of its impacts, especially given the passivity of the measures to combat it adopted to date. "Climate change is the straw that broke the camel's back on several critical elements of children’s health," said Aaron Bernstein, a pediatrician at Children's Hospital Boston and director of the course “Human Health and Global Environmental Change” at the Harvard School of Public Health.

Climate change is the major health challenge of the 21st century

"Although humans have proven themselves capable of living under various sets of extreme conditions, some communities have paid the consequences," said Sunyer. "But if the Earth's temperature rises two degrees Celsius over the coming years, no group will escape from suffering its adverse health effects.”

From the 18th to the 20th century the globe warmed by half a degree Celsius on average. Lately, this trend has increased. In Catalonia, between 1950 and 2008 the temperature has risen 0.2 degrees Celsius per decade, and forecasts call for significant increases of between one and five degrees Celsius by the end of the century.

No wonder, then, that in 2009 the prestigious journal The Lancet proclaimed climate change as the major health challenge of the 21st century: "The negative effects will outweigh the positive ones throughout the Earth if the global average temperature increases by two degrees,” Sunyer said.
"Climate change will affect the quality and quantity of food"
For years, scientists on the Intergovernmental Panel on Climate Change (IPCC, of the United Nations) have attributed climate change to human activity. “They have been increasingly forceful in their expression of this position, although scientists are usually extremely prudent" and tend to be conservative in their estimates, Sunyer said. But "while 99% of scientists believe that man is behind climate change, only 40% of the general population agrees," he said.

Temperature and crop health

An overpopulated planet, especially dense in coastal and urban areas, can not provide the necessary conditions to turn the current situation around. With currently six billion people inhabiting the planet, energy expenditure has increased by 35% in relation to the eighteenth century. And while at that time 3% of the human population lived in cities, now 47% does so. "A third of the planet’s biodiversity has changed and this has effects on human health and food production," Sunyer said. "If the temperature rises one degree, the production of major crops will fall by 10%," said Bernstein, who added, "most stable crops that present more carbon dioxide (CO2) have less protein, less zinc and less iron. For many children the main source of zinc are grains." For this doctor turned into a champion against climate change there is no doubt that "climate change will affect the quality and quantity of food."

The latest panels of the IPCC and the World Health Organization (WHO) are "more daring" when it comes to building bridges between health and climate change, Sunyer said. The emphasis is on diarrhea and malnutrition, while other studies draw a cause-effect relationship between temperature increases and the spread of salmonellosis and malaria. Moreover, "if winters are milder there will be fewer pneumonias,” Sunyer said, but “the seasons of pollen and associated allergies will be prolonged." And by endorsing the comments of Tony McMichael, professor at the National Centre for Epidemiology and Population Health at the University of Australia, he warned that "climate change involves direct effects (more floods and heat waves) as well as indirect ones (more pollution, less water resources, more vectors that can carry diseases, less arable land and less biodiversity)."

The effects of pollution

"At higher temperatures the harmful effects of pollution increase because certain toxic elements are more volatile and because it increases their oxidative capacity," Sunyer said. The most common air particulates are from atmospheric aerosols rich in aluminum, silicon, potassium, calcium, iron, zinc, titanium or lead. The Roger Torné Foundation warns that these elements penetrate deep into the lungs and can cause coughing, difficulty of breathing, the worsening of asthma, chronic bronchitis and emphysema. Traffic is the most common cause of air pollution in cities and polluted air can cause respiratory tract irritations. The atmosphere is also full of harmful particles from natural sources like dust stirred up by storms and wind erosion. In this sense, it is worth noting that 15% of the days per year Spain receives dust from the Sahara desert, increasing by 40% the amount of air particles and daily mortality by 8%.

Within households, cigarette smoke is the leading air pollutant. The respiratory system of children is more vulnerable than their parents'. It is less developed and less able to remove external contaminants, so that a household of smokers is more harmful to the young. Cleaning products also pollute the domestic atmosphere, while "good ventilation is essential and prevents moisture that can cause mold," Sunyer said.

Furthermore, fungi are on the rise and becoming a major environmental health problem. Flooding caused by Hurricane Katrina led to "aspergillosis problems among residents and volunteers in New Orleans not seen for years," according to Sunyer. As a result of the disaster, the air is full of fungi spores from the "biological load that accumulated in buildings as well as waste pollutants from chemical companies that become airborne due to earth movement caused by the floods."

Alterations in the water cycle

Floods and droughts will become more frequent over the coming years. This is indicated by several studies, which point to the global temperature increase as the cause. "The change in the world's average temperature will modify the distribution of heat and now there are more hot days. With just a one degree increase the number of hot days can double," Bernstein said. "And more people die summer than in winter," Sunyer added. A good example of this took place in August 2003, when a heat wave in Europe claimed 35,000 lives.

"With climate change, the water cycle is intensifying," Bernstein said. "In fact, it has redistributed the amount of annual rainfall and will continue. The amount of water remains the same, but it is increasingly concentrated in fewer months, in which it rains more intensely, so as to produce more droughts and more flooding. " Apart from the consequences described so far, the rise of forest fires must be added. "Drought and heat waves increase the risk of fire," Bernstein said. "In California and Greece (with major fires last year) it has already been seen that the fires have increased acute and chronic respiratory problems, especially asthma," Sunyer said.

The outlook is not encouraging and the scientific community appears to only see one solution: reduce the presence of permanent gases and air pollution, goals that can only be achieved through shifts in lifestyles, especially in industrialized countries.
HEAT KILLS
Between 1983 and 2006, an average of 348 people died annually in Catalonia due to heat, according to a study by Xavier Basagaña, CREAL biostatistics researcher. After analyzing more than 503,000 deaths during this 23-year period, the scientist established that, on average, during the hottest days mortality rose by 4%. And not only that, but the day following a day of a heat wave mortality increased by 10%. The main victims are over 65 years old. Heat waves (three consecutive days over 30º Celsius) involve increases in deaths from respiratory problems (28%), cardiovascular problems (24%), strokes (40%), nervous system complications (41%), urinary and renal tract problems (22%), diabetes-related ailments (28%) and suicides (29%). Children are very sensitive to high temperatures, and infant mortality soars by 25% in children under one year old on extremely heat days.

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