Cyclone Burevi which last week hit the Eastern coast of Sri Lanka leaving a trail of damaged houses and thousands of homeless persons has shifted national focus to the impacts caused on human beings especially on their health and quality of life. In their latest studies, weather experts believe the occurrence of such severe weather patterns shifting from extreme heat to extreme cold, from floods to droughts has surged in recent years and is mainly caused by human activities.
The Sunday Observer asked Family Physician, Ministry of Health, Dr Ramya L. Premaratne who has made an in-depth study of this subject to give us more insights into how and what causes extreme weather changes, and why it is necessary that we reduce greenhouse gas emissions to zero by 2050 at the latest.
Excerpts:
Q. Over the past several years rising temperatures have posed a threat to the environment and wildlife, raising public concern. What are the main factors that contribute to this surge in global warming?
A. There are several greenhouse gases responsible for global warming, and humans emit them in a variety of ways. Greenhouse gas is a gas that absorbs and traps heat in the atmosphere and warms the planet. Types of Greenhouse gases are carbon dioxide, methane, nitrous oxide and industrial gases such as hydroflurocarbons, sulphur hexafluoride and nitrogen trifluoride. These gases mostly come from the combustion of fossil fuels in cars, factories, and power plants. The gas responsible for the most warming is carbon dioxide. Other contributors include methane released from landfills, petroleum industries and agriculture, nitrous oxide from fertilisers, gases used for refrigeration and industrial processes; and the loss of forests that would release stored CO2. Excess greenhouse gases can cause Earth’s atmosphere to absorb more and more heat, causing it to warm up.
Q. What is the rate of increase in land and ocean temperatures? What has caused this spike?
A. According to the National Oceanic and Atmospheric Administration of US (NOAA), 2019 Global Climate Summary, the combined land and ocean temperature has increased at an average rate of 0.07°C (0.13°F) per decade since 1880; however, the average rate of increase since 1981 (0.18°C / 0.32°F) is more than twice as great according to the latest report dated August 14, 2020.
Causative factors vary, from human activity which has increased atmospheric CO2 concentration by 47% since the Industrial Revolution began. This is the most important long-lived climate change. Deforestation and burning fossil fuels is also a cause. Another reason is emission of nitrous oxide, another powerful greenhouse gas produced by soil cultivation practices, especially from the use of commercial and organic fertilisers, fossil fuel combustion, nitric acid production, and biomass burning.
Q. What is the impact of rising temperatures on humans?
A. Rising temperatures create climate change that result in prolonged droughts and unseasonal floods. Physical and mental health problems can occur due to extremes in weather and temperature, increased pollution and environmental toxins.
World Health Organization (WHO), researchers predict that certain effects of climate change will contribute to an increase of about 250,000 deaths per year between 2030 and 2050 from conditions such as: heat stress, malnutrition, diarrhoea and malaria. Rising temperatures can also cause a wide range of severe health problems. All these factors can impact human health, including increased risk of infections, respiratory problems from smoke exposure, malnutrition and death. Prolonged exposure to extreme heat can also cause, heat strokes, muscle cramps and worsen existing living conditions of the poor. Natural disasters caused by extreme weather events can have drastic adverse effects on children and older adults in poor and marginalised communities.
Q. Effects on the elderly and the young?
A. Heat stress from an increase in average temperatures can cause an increase in illness and death, particularly among the young, the elderly, the frail, and the ill, especially in large urban areas. Climate change will exacerbate an already large urban heat effect that exists in many large cities. Heat related mortality could be the largest direct health threat from global climate change including, extreme high temperature, light winds, high humidity, and intense solar radiation.
Q. Other adverse effects of ozone depletion you have not mentioned?
A. Skin cancer, cataract, and immune suppression .Ozone depletion can have both direct and indirect effects on ecological systems and human health. The most important direct human health effect would be an increase in skin cancers, especially, in fair-skinned populations.
These natural hazards can cause direct loss of life or injury and affect health indirectly through loss of shelter; population displacement; contamination of water supplies; loss of food production (leading to hunger and malnutrition); increased risk of infectious disease epidemics (including diarrhoea and respiratory diseases); and damage to infrastructure for provision of health. Increased temperatures also tend to expand the geographical range of malaria transmission.
In addition, due to depleted agriculture, live stock and fisheries industries from climate change, the food chain could affect the Food Production chain and thereby lead to a decline in nutritional health. It could affect the supply and quality of fresh water. Climate change may aggravate lack of access to clean and abundant drinking water, and even more those who are without adequate sanitation. At present the WHO estimates more than one billion people worldwide to be without access to safe drinking water, and approximately 1.7 million premature deaths every year due to lack of safe drinking water and sanitation.
Q. What about diarrhoeal diseases due to shortage of water supply?
A. Changes in surface water quality and quantity are likely to affect the incidence of diarrhoeal diseases. This group of diseases includes conditions caused by bacteria such as cholera and typhoid as well as parasitic diseases such as amoebiasis, giardiasis and cryptosporidium. Infections with cholera and typhoid bacteria are dependent on the concentration of the pathogens in water or food. Higher temperatures, changes in precipitation and climate variability would alter the geographical range and seasonality of transmission of many vector borne diseases.
Q. Can infectious diseases such as dengue and malaria also spike due to extreme climate changes?
A. Heavy rainfall tends to overflow containers and can thus discourage vector breeding, while extended drought conditions have in some cases led to higher vector abundance due to increased use. Temperature, rainfall, humidity, and wind each play a role in determining the distribution and incidence of malaria. These factors govern the distribution, prevalence, rate of development, life span, and feeding frequency of the Anopheles mosquitoes. Temperature also plays a fundamental role in the rate of multiplication of the parasite in the mosquito.
Q. Anaemia? Recent reports show many Lankans suffering from anaemia and malnutrition.
A. Yes. Anaemia caused by malnutrition is a major public health problem contributing to maternal and child morbidity and mortality. The cause for anaemia is iron deficiency due to lack of nutritious food intake by people. Usually this happens because of a decrease in food supply or the quality of food, and impacts mostly marginalised communities.
Q. Increased temperatures have also been linked to asthma and other respiratory problems. Do you agree?
A. Yes. Since the respiratory surfaces are the primary route by which air pollutants enter the body, the activation of thermoregulatory responses at pulmonary level during prolonged heat exposure may augment the total intake of airborne pollutants due to the increase in ventilation rate and lung volumes. Temperature may also influence the interaction between allergens and air pollution in producing adverse respiratory effects since air pollution-related damage to the respiratory epithelium increases airway permeability stimulating allergen-induced responses and absorption of pollutants. Extreme heat could also lead to deaths due to cardiopulmonary causes.
Q. As Sri Lanka is in the midst of a Covid-19 outbreak, fears have been raised that the current extreme weather changes can increase the risk of people being exposed to this disease. Your comments?
A. I do not think there is any direct connection between global warming and fast spreading of Covid-19.
The reasons for spreading of Covid-19 are mainly due to the three Cs:
Crowded places with many people close to each other
Close-contact settings, especially where people have conversations close to each other
Confined and enclosed spaces with poor ventilation.
The risk of Covid-19 spreading is higher in places where these ‘3Cs’ overlap.
Q. Safe waste disposal of contaminated gloves, e-waste, face masks etc has been repeatedly emphasised by the Health Ministry which has now laid down rules for this. Is this good?
A. This will regulate the disposal of medically and clinically hazardous waste. According to the interim guidelines prepared by the Health Ministry, waste and potentially contaminated items such as face masks, masks, gloves, handkerchiefs, tissues, sanitary pads, diapers, and other materials contaminated by body fluids should be collected in a leak-proof yellow colour HDPE (minimum thickness of 25 microns or 100 gauge) or LDPE (minimum thickness of 55 microns or 250 gauge) polythene bag. If a yellow bag is not available, a yellow colour plastic strip or a piece of cloth must be attached or tied enabling identification of the special waste bag from a distance. All waste containers/bags should be kept in a secure place outside the reach of children and animals until discharge or disposal.
Q. Lighting of fireworks is traditionally practised during festive seasons. However, this practice has been discouraged. With the upcoming festive season do you think this is a step in the right direction?
A. Yes, for more than one reason. It has to be discouraged because it is beneficial health wise and would also reduce global warming. First, from the point of view of health, lighting of fireworks has to be discouraged because it emits hazardous air pollutants to the atmosphere. Fireworks cause extensive air pollution in a short amount of time, leaving metal particles, dangerous toxins, harmful chemicals and smoke in the air for hours and days.
Some of the toxins never fully decompose or disintegrate, but rather hang around in the environment, poisoning all they come into contact with. Exposure to fine particles, like those found in smoke and haze, is linked to negative health implications, such as coughing, wheezing, shortness of breath, asthma attacks and even heart attacks, according to the EPA. People at greatest risk are those with heart or lung disease, older adults and children. Secondly, it reduces excessive heat sent into the air.
Q. Have you a message with regard to reducing the negative impacts of global warming, for our readers?
A. Global warming is mostly man-made. As human beings we share a collective responsibility to reduce greenhouse gas emissions to zero by 2050 at the latest. We can do this by reducing vehicular emissions, stop burning of fires outside, using less firewood for cooking and using less heat raising devices inside our homes.