36 CLIMATE CHANGE, GENDER AND HUMAN HEALTH

Prof. (Dr.) Jayanand Prof. (Dr.) Jayanand

Objectives

explain about the changing climate around the globe;
state the impact of climate change on human health;
distinguish between direct and indirect effects of climate change;
describe the influence of changing climate on different sections of society; and
summarise the impact of climate change on human psychological developments.

Contents

Introduction

Learning Objectives

Climate Change and Human Health

Direct Impacts of Climate Change on Human Health Temperature Related Deaths and Illnesses Pollution

Sulphur dioxide (SO2)

Nitrogen dioxide (NO2)

Carbon monoxide (CO)

Suspended Particulate Matter (SPM)

Ozone

Benzene

Volatile Compounds

Lead Particles

Indirect Impacts of Climate Change on Human Health Infectious Diseases

Vector-Borne Diseases

Water-Borne Diseases

Algal Bloom

Differential Impacts of Climate Change on Different Sections of Society Gender Wise

Age Wise

Social and Economic Status Wise

Impact of Climate Change on Mental Health and Well-Being

Summary and Conclusions

References

Web Links

Multiple Choice Questions

Answers to MCQs

Introduction

You have already studied about climate change and it evidences and causes in the previous modules of this course. You have also learnt about the role of human beings as being a major agent of this climate change. The present module deals with the changing climate conditions around the globe and its impact on human health. The learners will gain an outlook about effects of climate change on different sections of the society with special emphasis on the developing countries. They will also get acquainted with the direct and indirect impacts of climate change and their roles in modulating the mortality and morbidity among the population. Insights will be developed regarding the impacts of climate change on mental health and wellbeing.

Climate Change and Human Health

In the blithe radiance of the rapidly blooming economy and scientific and technological advancements, their impact on nature and environment has usually been overlooked. This has caused severe damage to the human beings who have been sustaining the change in climatic conditions over the earth, in the form of shrunken glaciers, frequent flood incidences, droughts, cyclones, increased global temperature, changes in the precipitation patterns, rise in sea levels etc. These changes in climatic conditions sabotage access to safe water, adequate food, clean air, shelter and security.

As per a report of World Health Organisation (WHO), 12.6 million lives are compromised each year by preventable ecological risk factors. The report further ascertained that climate change is expected to cause approximately 2,50,000 additional casualties per year due to malnutrition, malaria, diarrhoea and heat strokes between the year 2030 and 2050. It is likely to increase the expenses of billions of dollars for the recuperation of human health. The scenario is more or less similar in Asian and Indian perspective with the effects ranging from extreme weather conditions to variations in the incidence of vector-borne diseases.

South Asia has specifically witnessed increased frequency of floods due to heavy rainfall. In 2007, around 2,000 human lives succumbed to floods resulting from monsoon, while more than 20 million people lost their dwellings in Bangladesh, India and Nepal. Floods also create conducive environments for the growth and spread of numerous life-threatening pathogens. Human or animal waste contaminated floodwater escalates the incidences of faecal-oral route mediated disease transmission, diarrhoeal disease and other bacterial and viral illnesses such as cholera, dysentery and typhoid. The situation is aggravated in developing countries where lack of appropriate flood control mechanisms, poor sanitation infrastructure and sluggish surveillance activities to detect and control outbreaks add fuel to the fire. Flooding provides the breeding grounds for mosquitoes and other insect vectors and thus contributes to increased vector- and rodent-borne infections diseases. Having an idea about the effects of climate change on human health, we are now in a position to categorize them under different sections like its direct and indirect impacts as discussed in the coming sections.

Direct Impacts of Climate Change on Human Health

The direct impacts of climate change depend mainly on exposure to heat or cold waves or extreme weather events and their subsequent influences on human health in the form of various heat- and cold-related illnesses and sometimes deaths.

Temperature Related Deaths and Illnesses

The daily morbidity and mortality has been shown to have a direct association with the extreme outdoor temperatures especially in the temperate and subtropical countries. Morbidity is a state of diseased, disabled or poor health conditions, while the mortality rate may be defined as a measure of the number of deaths in a given population. Nevertheless, we can easily comprehend that the rate of mortality ascends much more steeply with rising temperatures than with falling temperatures. Both morbidity and mortality could also increase in different regions of the world as a result of the expected increase in the number of days with high daily temperatures (i.e., the persistence of days with above average maximum and minimum temperatures). The impacts would be exacerbated by high humidity, intense solar radiation and frail winds. All of these factors affect the physiological mechanisms of human adaptation for the better survival and ultimately lead to poor living and health conditions among the population. These conditions are magnified with the people with low income as they have lesser capability to cope with. Though, there is impact of increasing temperature to everyone, the most vulnerable are the poor people.

Global warming, the most burning environmental concern of 21st century, is subject we all are familiar with. Global warming could severely augment the number and sobriety of extreme weather events such as storms, floods, and droughts and related landslides and wildfires. A number of slums and human settlements located on hills and flood-prone areas are subjected to periodic natural calamities that adversely impinge on human health. These congested peri-urban settlements with inadequate government services also becomes a potential breeding ground for a plethora of disease hosts (e.g., rats, mice, cockroaches, flies) and infectious microorganisms, thereby challenging the resident population’s vulnerability. The communities surrounded by these poverty stricken belts also become more susceptible to episodic pandemics (WHO Commission on Human Health and Environment, 1992).

Pollution

Pollution, especially air pollution, is yet again the most conversed environmental concerns of our times. Here, however, we would try to study its vicious impacts on human health. Elevated amount of air pollutants, especially particulate matters, operate synergistically to influence mortality rate of a population especially in big urban cities, like Mexico City, Santiago and Chile where such conditions enhances the formation of secondary pollutants (e.g., ozone). People inhabiting urban and industrial areas are predominantly prone to various diseases and ailments due to a variety of air pollutants which chiefly include sulphur dioxide, nitrogen dioxide, carbon monoxide, ozone, volatile organic compounds etc.

Now let us study the harmful effects of different pollutants on human health separately.

a) Sulphur dioxide (SO2): Individuals persistently in contact with Sulphur dioxide have elevated prevalence of cold, cough, fatigue, shortness of breath and bronchitis. A large portion of atmospheric SO2 is transformed to sulphate salts, which either settle down or contribute to acid rain in the form of sulphuric acid on reaction with the rain water. Exposure to 0.4 ppm (parts per million) SO2 or more results in asthmatics even after 5 minutes long exposure. Children and immunocompromised patients are especially susceptible to cough even with intermittent exposure to 1.0 ppm SO2.

b) Nitrogen dioxide (NO2): Similarly, higher levels of NO2 render human vulnerable to acute respiratory disorders like bronchitis, chronic fibrosis, emphysema and bronchopneumonia and lead to decline in optimum pulmonary operations. An elevation of 20% respiratory tract related maladies have been reported as a consequence of the increase in 30µg/m3 in NO2 levels. Incessant contact with approximately 2.0 ppm NO2 may cause far-reaching alterations in lung morphology (bronchiolitis) as well as lung dispensability.

c) Carbon monoxide (CO): Carbon monoxide is particularly lethal by virtue its tendency to competitively bind to haemoglobin (Hb) with higher affinity (240 times) in red blood cells (RBC) resulting in the formation of Carboxy Haemoglobin (COHb), thereby preventing the binding of oxygen and oxyhaemoglobin (O2Hb) in the normal conditions. Acute decrement in lung functions have been associated with high dose exposure of CO. About 5% CO exposure causes cardiovascular effect in young healthy, non-smoking individuals leading to fatigue and reduced ability to work. It may also lead to cardiac strokes, hypertension etc. Substantial evidences have suggested strong correlation between CO exposures and the consequent decline in birth weight, cardiomegaly, impediment in behavioural development, interference in the development of normal cognitive functions and an incline in even infant death syndrome.

d) Suspended Particulate Matter (SPM): Further, suspended particulate matter may also get deposited on skin and lead to skin related maladies, such as rashes, skin infections, blockages of pores etc. However, certain groups of particles pass into the respiratory tract through inhalation. The symptoms are often recorded as stuffy or running nose, sinusitis, sore throat, wet cough, head cold, hay fever, burning or red eyes, wheezing, dry cough, phlegm, shortness of breath, chest discomfort and pain. Chronic exposure to such particles leads to asthma and several lung related diseases. The bronchitis or pneumonia with pre-existing heart problems may lead to cardio-vascular mortality.

e) Ozone: The level of ozone in the atmosphere especially in urban population has risen beyond the average values. It is responsible for the onset of serious human health conditions such as irritation in eyes, nose and throat, discomfort in respiration, cough and headache. Ozone irritates the epithelial lining of pulmonary organs. Exposure of even 1 to 3 hours with ozone at a concentration ranging between 235-314µg/m3 may result in acute reversible impairment of lungs functioning and enhanced respiratory disease symptoms. However, prolonged ozone exposure leads to grave pulmonary inflammations, besides increasing the susceptibility of lungs towards an assortment of bacterial infections and compounding the severity of influenza infection.

f) Benzene: Benzene is a hazardous air pollutant which accelerates the generation of carcinogencity (cancer causing ability) in the system and is associated with several genetic aberrations and chromosomal anomalies etc. People may suffer from euphoria followed by dizziness, erratic breathing rate, headache, nausea and unconsciousness by long duration exposure to even minor concentrations of benzene. Blood and bone marrow related disorders, anaemia, lower ability of blood clot, immune system impairment along with reproductive and development complications have also been reported with frequent exposures to benzene. Women may be subjected to certain menstrual disorders, while retardation of foetal development has also been reported.

g) Volatile Compounds: The volatile compounds have tremendous impending carcinogenic effects on human beings and are suitably termed as air toxins. They react with oxides of nitrogen in the presence of sun light to generate photochemical smog. We must have heard of this smog being an awfully dense haze that hampers the visibility in the region. These vision obscuring fumes cause irritation to eyes and lungs, besides damaging the plant life.

h) Lead Particles: They may enter human body system through inhalation or ingestion with contaminated food or water. Lead is a dangerous environmental pollutant and has adverse effects on practically every system in human body. It can damage the kidneys, the nervous system, reproductive system and cause high blood pressure. Children are more prone to lead pollution due to higher absorption rate than adults. It affects the development of brain of foetuses and young children resulting in lack of intelligence, neurological problems, behavioural problems and depleted concentration levels. Chronic exposure with elevated blood lead levels is associated with hypertension, headache, confusion, irritability, focal motor dysfunction and insomnia in adult males too.

Figure 1 very clearly exhibit some of the pollutants and their negative impacts on several organs of the human body and overall on human health.

Figure 1: Effects of Pollution on Human Health

Indirect Impacts of Climate Change on Human Health

Now let us get acquainted with the indirect impacts of climate change on human health. These are in the form of diseases such as infectious diseases, vector and water-borne diseases and algal blooms.

a) Infectious Diseases: Infectious and parasitic diseases are the prime cause of high morbidity in adults and mortality among children since ancient times. Some infectious diseases are more common in tropical and subtropical areas than in temperate or cold areas. Majority of them are food, water-borne infections. Viral, bacterial, and protozoan agents of diarrhoea can survive in warm water for long duration of time and thus spread at increased rates in rainy seasons in the tropical and sub-tropical climates.

b) Vector-Borne Diseases: Now let us understand the role of changing climate on the prevalence of vector-borne diseases. These mainly encompass vector borne contagions such as dengue and chikungunya fever, parasitic infections like leishmaniasis, lymphatic filariasis, onchocerciasis and tick-borne diseases. The distribution of dengue and chikungunya arboviruses are also influenced by climate, as both share a mutual vector Aedes aegypti. Malaria is another vector borne disease, spread by several species of female Anopheles mosquitoes, whose population is majorly affected by temperature, surface water, and humidity. Climatic factors have also induced human plague, a kind of bacterial disease having rodents as disease carrier and fleas as transmittance agents. Temperature and rainfall are two key determining factors having effects on survival and growth of rodent and flea population, abundance and dispersal. Another disease showing similar climate sensitivity is Murine typhus, a rickettsial disease, also transmitted by fleas.

All the infective agents mentioned above and vectors are sensitive to environmental changes, especially those nurtured by their respective optimum temperatures and humidity. Vectors also are vulnerable to airstream, soil moisture, surface water and variation in vegetation and forest distribution. All these environmental components influence the population distribution of vectors along different geographical locations as well as their behavioural pattern. Precipitation is another crucial factor that provides the aquatic environment required for the completion of a specific life cycle of vectors. Such breeding places are increased and maintained by rainfall. Winds may also contribute to the dispersion of some flying insects, such as mosquitoes, blackflies, and sandflies.

c) Water-Borne Diseases: Hot and humid climatic conditions bestows upon the water borne pathogens to thrive and proliferate at rapid rate, thereby making the water-borne diseases recurrent. The list of such diseases ranges from cholera to different forms of diarrhoea. Diarrhoeal diseases constitute one quarter of the total childhood fatality and thus are already the foremost cause of morbidity and mortality in South Asia. With the rising temperature, the time period of bacterial survival and propagation is expected to rise, thereby leading to a direct elevation in the incidence of diarrhoeal diseases. Primarily the unsafe drinking water and lack of basic sanitation along with depleting levels of freshwater synergistically aggravate the situation which is likely to worsen in the near future if remained unbridled. Rapid urbanization and industrialization, population explosion, inefficient water use and lethargic and apathetic attitude of people towards water conservation are already causing water shortages several countries around the world. The situation of dearth of freshwater resources is aggravated by the continually deteriorating average annual rainfall with each passing year, which is a direct consequence of climate change in many of these areas. Consequently people are left with limited choices of using comparatively contaminated and unsafe water from other perilous sources which gives the required vent for several water borne disease outbreaks. The situation is worsened in monsoon and floods that presents plenty of such contaminated water sources for the breeding and spread of numerous water borne ailments.

d) Algal Blooms: Algal blooming may also be associated with contamination of aquatic creatures including fish and shellfish. With the continually warming ocean, temperature sensitive toxins are produced by phytoplankton that contaminates the seafood, resulting in an increased frequency of food poisoning in humans in the coastal areas. The climate induced changes in terms of production of aquatic pathogens and biotoxins may jeopardize seafood safety.

Refer to Figure 2 to get a brief idea of the impact of climate change on human health.

Figure 2: Impact of Climate Change on Human Health

Source: https://www.cdc.gov/climateandhealth/effects/default.htm

Differential Impacts of Climate Change on Different Sections of Society

So far we have discussed the direct and indirect consequences of climate change on humans. In this section, we shall try to identify how climate change influences different sections of society in terms of gender, age and socio-economic conditions.

Gender Wise

In this regard, it is worth to mention that gender plays a crucial role in deciding an individual’s vulnerability. Women are more likely to be affected adversely by climate change than men. Their vulnerability is further increased due to their social and economic status which limits their ability to adapt to the altering climatic conditions. Pregnant women are in particular more prone to malaria than non-pregnant women by virtue of various physiological changes, like increased temperature of exhaled breath and heat dissipation. The condition renders pregnant ladies to be more alluring to malaria carrying mosquitoes, making them particularly vulnerable to malaria. Women in the advanced phase of pregnancy (having gestational age of more than 28 weeks) exhale more than 21% of the average volume as compared to non-pregnant ladies. They also have increased blood flow through their skin, which leads to greater heat dissipation form their epithelial surface especially of the hands and feet. With due significance of immunity and nutrition in mind, physiological and behavioural changes occurring during pregnancy play substantial roles in augmenting the risk of malarial infection in pregnancy, which subsequently pose serious threats of spontaneous abortion, premature delivery, stillbirth and low birth weight.

Floods and water logging is other impacts of climate change that has given rise to differential health effects in women and men in flood affected regions. Women are compelled to stay in close proximity of the community and drink unhygienic water. Pregnant women face additional difficulty with locomotion in marooned and slippery conditions and thus are often advised to stay at home. A large portion of major gynaecological problems usually arise due to unhygienic water usage. Nevertheless, the nutritional status determines the capability of an individual to cope with the aftermath of natural disasters. Girls and women with relatively poor nutritional status often suffer from increased prevalence of anaemia, pregnancy and parturition (process of delivering the baby) related complications, higher intrauterine growth retardation rates, low birth weight of newly born and perinatal mortality.

Age Wise

The effects of climate change seem to be more pronounced on children and aged population as compared to adults. Children have to contend with the immediate and life-threatening dangers of climate-related disasters, food insecurity, rising air pollution, increased risk of vector-borne diseases, acute respiratory infections, diarrhoeal diseases and malnutrition. Evidence is increasingly showing that these risks can have a markedly detrimental impact on a child’s early development. Children’s vulnerability to vector-borne diseases such as dengue, malaria, and diseases associated with poor water quality, inadequate sanitation and poor hygiene practices, such as diarrhoeal diseases is also far higher than adults. In 2015, malaria is estimated to lead to 4,38,000 deaths, of which more than two-thirds are children under 5 years of age.

Like children, elderly population are also vulnerable to the risks and challenges posed by the changing climate around the globe. With the increasing biological age, people have to confront several challenges including declining physical and mental wellbeing, higher risks of health related disabilities, loss of financial stability and security and ultimately sudden or painful demise. An older person’s sensitivity to the effects of climate change is determined by hereditary disposition, their personal history of disease or health conditions, income, family support systems, quality of public health infrastructure and access to relevant local information.

Social and Economic Status Wise

Climate change compounds the miseries of people with low income and social status. The adverse impacts of varying environmental conditions are prominent in the developing nations due to their geographical location and native climatic conditions. Their high dependence on natural resources and their limited capacity to adapt to a changing climate makes situation worse. Alterations in both temperature and rate and amount of precipitation vary from region to region, affecting higher and lower latitudes differently. This would change the frequency of natural disasters such as droughts and floods which may adversely affect agricultural production, fisheries, marine life, water resource availability, industry and human health. All these are expected to increase the disparity in wealth between the developed and developing world. The effects are perceptible not only in terms of disparity in wealth but also in relation to health and survival of the two groups of population. In the absence of effective and well implemented policies of protection, the coastal flooding could grow tenfold or more by the 2080s and affect more than 100 million people per year due to sea-level rise alone.

Pollution has its own role in aggravating the hardships and misery of poor. In the eastern parts of India and Bangladesh, having predominantly higher arsenic contamination of groundwater, inundations resulting from severe downpour or oceanic calamity compounds the trials and tribulations of socially and economically deprived sections of the society. Arsenic poisoning has been observed to be drastically impacting the educational and nutritional status of the members of these groups. Physiologically arsenic toxicities are reflected in the form of skin related maladies like lesions, hardening, dark spots on the hands and feet, swollen limbs and loss of sensation.

Impact of Climate Change on Mental Health and Well-Being

The effects of climate change and its related environmental consequences are not only confined to the physical health but also affect mental and psychological wellbeing of a person. In this section we shall try to surface and correlate the different ways by which any alteration in average weather conditions affect the intellectual integrity of sufferers. To start with, we know that global warming has led to an unprecedented increase in the optimum universal temperature, a trend that is likely to continue. This rise in global temperature has been associated with the increasing aggressiveness and violence among people. A direct relation between higher incidences of criminal activities in summers substantiates the above statement. This aggressive behaviour and aggressive mentality often leads to several suicide attempts, the counts of which have been found to soar in hot summers indicating a relationship between these violent activities with the recent rise in mercury.

Heat waves have also been linked with anomalous psychological and behavioural responses. An Australian study reported the complementary effects of heat waves in increased prevalence of mental disorders in conjunction with other physiological ailments including cardiovascular, hepatic and renal illnesses. Different mood disorders, anxiety disorders, dementia etc. are the common cerebral limited consequences of heat waves. We have all experienced that severe heat exposure renders us physically and psychologically exhausted. Occupational heat exposure, i.e. prolonged contact with elevated temperatures at workplace adversely affects the workers’ cerebral consistency and causes severe mental stress as reported by a study from Thailand, which is often reflected in their deteriorating performances.

Besides, certain environmental calamities have their own roles in causing stress related psychiatric symptoms among the survivors. Disasters like floods, hurricanes, and bush-fires often leave drastic traumatic mental indentations that sometimes take years to heal. People subjected to life threatening circumstances often develop serious Post-Traumatic Stress Disorder (PTSD), the symptoms of which encompass regular disturbing flashbacks of the calamity.

Drought is another major consequence of climate change whose frequency of occurrence is expected to rise in the near future. With aberrant patterns of precipitation and soaring temperatures, droughts are already showing their grave corollaries in the form of severe water scarcity, drop in ground water levels, extreme weather conditions and many others. All these unanimously result in awful agricultural losses in terms of crop productivity, which ultimately leads to increased distress to farmers. Those farmers who are not able to cope with these hardship, they are taking extreme steps and ultimately suicide. The incidents are expected to even aggravate the present situation with increased drought due to climate change in near future. Such events have been observed in the developed as well as developing nations like India. Psychosomatic anxieties are thus amplified subsequent to disasters, especially for the families who are completely dislocated from their native settlements and forced by the destiny to subsist in any relief camps under emergency situations. Complete breakdown of normal daily routines along with excessive congestion at these emergency camps and lack of privacy add up to the already existing traumatic frame of mind of the victims and give vent to excessive annoyance, disappointment and aggression, with women and children forming the most vulnerable groups.

Summary and Conclusions

Extreme environmental conditions including floods, droughts, forest fires, and tropical cyclones are becoming more prominent these days. Changing climate conditions around the globe have remarkable impact on human health. The impacts of the climate change on human being could be grouped into two – direct and indirect.

The direct impacts of climate change are probably due to exposure to heat or cold waves or extreme weather events which are basically temperature and humidity related changes in climate. Air pollution in the form of rise of certain greenhouse gases like SO2, NO2 and also CO, lead, benzene, SPM in air also directly impact human health. Indirect impacts of climate change on human health are due to certain infectious diseases, vector-borne and water-borne diseases. Algal blooms are the rapid growth of algae that can cause harm to animals, human, or the local ecology.

Climate change influences different sections of society in terms of gender, age and socio-economic conditions of the people. Women are more likely to be affected adversely by climate change than men. The effects of climate change seem to be more pronounced on children and aged population as compared to adults. Climate change compounds the miseries of people with low income and social status. The effects of climate change and its related environmental consequences are not only confined to the physical health but also affect mental and psychological wellbeing of a person.

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References

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