24/7 Support - 021 556 3990

News and Updates

Job Blog Health Day banner

The past 50 years were characterised by significant health issues such as mental health, maternal and childcare, and climate change. Celebrating World Health Day is attributed to activities that extend beyond the day itself and serves as an opportunity to focus worldwide attention on these important aspects of global health. From its inception at the First Health Assembly in 1948 and since taking effect in 1950, the celebration has aimed to create awareness of a specific health theme to highlight a priority area of concern for the World Health Organization (WHO).

https://www.who.int/westernpacific/new/events/world-health-day) Accessed I March 2021.)

What is health?

WHO defines health as being “a state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity” in 1948.



What is climate? how is it different from weather?

Weather is the variations we see and feel outside from day to day, e.g., one day it might rain and the next day it may be sunny. Sometimes it is cold and sometimes it is hot, and weather also changes from place to place. In one place people might be wearing shorts and are tanning, while elsewhere it may be so cold that people prefer to stay indoors

Climate is the usual weather of a particular place. A place might be mostly warm and dry in the summer, while the same place may be cool and wet in the winter. Different places can have different climates. You might live where it snows all the time, and some people live where it is always warm enough to swim outside! Then there’s also earth’s climate. The earth’s climate is all the combined climates around the world together

(Dunbar: 2017).

Is the earth’s climate changing?

The earth’s climate is ever-changing. There have been times when the earth’s climate has been much warmer than it is currently and there have been times when it has been cooler. These times can last thousands or millions of years. People who study the earth see that the climate is getting warmer. Earth’s temperature has gone up about one degree Fahrenheit in the last 100 years. This may not seem like much, but small changes in temperature can have big effects. Some effects are already happening. The warming of earth’s climate has caused some snow and ice to melt. The warming also has caused oceans to rise, and it has changed the timing of when certain plants grow (May: 2017).


The impact of climate change on sick and healthy people

The influence of climate change includes increased temperatures, changes in condensation, increases in the frequency or intensity of some extreme weather events, and rising sea levels. These impacts threaten our health by affecting the food we eat, the water we drink, the air we breathe, and the weather we experience. The severity of these health risks will depend on the ability of public health and safety systems to address or prepare for these changing threats, as well as factors such as an individual’s behaviour, age, gender, and economic status. Impacts will be based on where a person lives, how sensitive they are to health threats, how much they are exposed to climate change impacts, and how well they and their community can adapt to change. People in developing countries may be the most vulnerable to health risks globally, but climate change poses significant threats to health even in wealthy nations.

Climate change, congruent with other natural and human-made health stressors, influences human health and disease in numerous ways. Some existing health threats will intensify, and new health threats will emerge and not everyone is equally at risk. Important considerations include age, economic resources, and location. Preventive and adaptive actions, such as setting up extreme weather early warning systems and improving water infrastructure, can reduce the severity of these impacts, but there are limits to the effectiveness of such actions in the face of some projected climate change threats. The effects of climate change are a global matter, which should be considering the preparation of actions, interventions, and disaster plans. Climate change is affecting some of the essential factors that influence human health, including:

  • safety of shelter
  • air quality
  • quality, safety, and supply of drinking water
  • food availability
  • nutrition levels in food

As climate change progresses, researchers expect an increase in related health issues. According to 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:

Climate change can also contribute to migration, as factors such as drought and plummeting fish stocks can lead rural populations to move into urban centres. Living in urban areas can increase the risk of disease due to overcrowding and higher temperatures.

Wide-ranging health impacts

Air pollution

Climate change is projected to harm human health by increasing ground-level ozone and/or particulate matter air pollution in some locations. Ground-level ozone (a key component of smog) is associated with many health problems, such as diminished lung function, increased hospital admissions and emergency room visits for asthma, and increased premature deaths.

(Dennekamp, & M. Carey, 2010: Air quality and chronic disease: Why action on climate change is also good for health. New South Wales Public Health Bulletin] Anderson, Krall, Peng, & Bell, 2012: Is the relation between ozone and mortality confounded by chemical components of particulate matter? Analysis of 7 components in 57 US communities. American Journal of Epidemiology).

An increase in air pollution can pose a high risk to health. Higher levels of dust, ozone, and fine particles in the air can all reduce air quality and cause or exacerbate a range of health issues, including:


Warmer temperatures can lead to an increase in pollen production. An increase in carbon dioxide can lead to higher levels of allergens from plants. As a result, people may experience the following effects:

  • greater sensitivity to allergens
  • asthma, including longer or more frequent bouts of acute asthma
  • worsening of other respiratory conditions


Food insecurity

Weather changes affect crops and food production. Food prices may rise, which may cause people to adopt less healthy diets. Poor diets can lead to hunger, malnutrition, or obesity. According to the CDC, the nutritional value of certain foods may decrease due to climate change. Experts predict that increased carbon dioxide levels in the atmosphere and changes to the nutrients in the soil will result in fewer nutrients in many crops.

  • The likely increase in weeds and pests will also mean that farmers need to use greater amounts of herbicides and pesticides. These substances can be toxic to the people working with crops, as well as to those eating them.
  • Developmental and neurological issues. Exposure to toxins in the environment and stress-related effects of climate change can have a negative effect on neurological health.
  • According to the National Institute of Environmental Health Sciences, scientists believe that environmental factors play a role in the development of both Parkinson’s diseaseand Alzheimer’s disease.
  • Toxins in food and water can also lead to health issues in a developing foetus. For example, climate change can cause harmful algal blooms, which increase the biotoxins in fish and seafood. An increase in heavy metals, such as mercury and lead, contaminating seafood can lead to a reduced IQin a developing foetus.

Who is most at risk?

Although all populations are likely to experience the effects of climate change, certain areas of the world are more at risk than others. Areas most at risk from the health effects of climate change include:

  • coastal regions
  • mountainous regions
  • polar regions
  • small islands
  • megacities
  • countries with a lack of healthcare facilities
  • developing countries

Certain groups of people are also more at risk from the health hazards of climate change. They include:

  • children, particularly those living in developing countries
  • older adults
  • people with certain pre-existing health conditions
  • people who are economically disadvantaged
  • people who are socially isolated (SampsonLeonard: 2020)


Climate change is currently increasing the vulnerability of many forests to wildfire. It is projected to increase the frequency of wildfire in certain regions of the United States. Long periods of record high temperatures are associated with droughts that contribute to dry conditions and drive wildfires in some areas. Wildfire smoke contains particulate matter, carbon monoxide, nitrogen oxides, and various volatile organic compounds (which are ozone precursors) and can significantly reduce air quality, both locally and in areas downwind of fires. Smoke exposure increases respiratory and cardiovascular hospitalisations, emergency department visits, and medication dispensations for asthma, bronchitis, chest pain, chronic obstructive pulmonary disease (commonly known by its acronym, COPD), and respiratory infection

(Spracklen, Logan, Mickley, Park, Yevich, Westerling, and & Jaffe, 2007: Wildfires drive inter-annual variability of organic carbon aerosol in the western US in summer. Geophysical Research Letters, 34, L16816, doi: 10.1029/2007GL030037).

Temperature extremes

Extreme heat events have long threatened public health in the United States. Many cities, including St. Louis, Philadelphia, Chicago, and Cincinnati, have suffered dramatic increases in death rates during heat waves. Deaths result from heat stroke and related conditions, but also from cardiovascular disease, respiratory disease, and cerebrovascular disease.

(Zhang, Rood, Michailidis, Oswald, Schwartz, Zanobetti, Ebi, & O’Neill, 2012: Comparing exposure metrics for classifying ‘dangerous heat’ in heat wave and health warning systems. Environment International, 46, 23-29).

Disease carried by vectors

Climate is one of the factors that influence the infusion of diseases borne by vectors (such as fleas, ticks, and mosquitoes), which spread pathogens that cause illness. The geographic and seasonal distribution of vector populations, and the diseases they can carry, depend not only on climate but also on land use, socioeconomic and cultural factors, pest control, and access to health care, and human responses to disease risk, among other factors. Daily, seasonal, or year-to-year climate variability can sometimes result in vector/pathogen adaptation and shifts or expansions in their geographic ranges. Such shifts can alter disease incidence depending on vector-host interaction, host immunity, and pathogen evolution. North Americans are currently at risk from numerous vector-borne diseases, including Lyme dengue fever, West Nile virus, Rocky Mountain spotted fever, plague, and tularaemia. Vector-borne pathogens not currently found in the United States, such as chikungunya, Chagas disease, and Rift Valley fever viruses, are also threats.

(Nakazawa, Williams, Peterson, Mead, Staples, &Gage, 2007: Climate change effects on plague and tularaemia in the United States. Vector-borne and Zoonotic Diseases, 7, 529-540. Doi: 10.1089/vbz2007.0125)


Mental health and stress-related disorders

Mental illness is one of the major causes of suffering in the United States, and extreme weather events can affect mental health in several ways. First, following disasters, mental health problems increase, both among people with no history of mental illness, and those at risk – a phenomenon known as “common reactions to abnormal events.” These reactions may be short-lived or, in some cases, long-lasting. For example, research demonstrated high levels of anxiety and post-traumatic stress disorder among people affected by Hurricane Katrina, and similar observations have followed floods and heat waves. Some evidence suggests wildfires have similar effects and all these events are increasingly fuelled by climate change.

(McFarlane, & Van Hoof, 2009: Impact of Childhood Exposure to a natural disaster on mental health: 20-year longitudinal follow-up study. The British Journal of Psychiatry, 195, 1420148, doi: 10.1192/bjp, bp. 108.054270).

Prevention provides protection

Prevention is a central dogma of public health. Many conditions that are difficult and costly to treat when a patient gets to the doctor could be prevented before they occur at a fraction of the cost. Similarly, many of the larger health impacts associated with climate change can be prevented through early action at a significantly lower cost than dealing with them after they occur. Early preventive interventions, such as early warnings for extreme weather, can be particularly cost-effective. As with many illnesses, once impacts are apparent, even the best adaptive efforts can be overwhelmed, and damage control becomes the priority.

“Twenty-five years ago, people could be excused for not knowing much, or doing much, about climate change. Today we have no excuse

-Desmond Tutu, Former Archbishop of Cape Town