Climate Change and Human Health

Health Consequences of Climate Change
Health Consequences of Climate Change | Source

How Does Climate Change Effect Human Health?

We hear a lot about whether or not global warming is a real or imagined phenomenon, how global warming will affect the environment, and how humans are contributing to global warning. What we haven’t heard so much about, is how climate change in general affects human health, or what, if anything, humans can do to prevent or prepare for the impact of climate change on human health. Climate change might include global warming, but also includes heat waves, blizzards, hurricanes, floods, cold fronts, or any other changes in climate that could be natural or caused by humans directly or indirectly.

The National Institutes of Health (NIH) is the federal agency responsible for conducting medical research and for investigating causes, treatments and cures for diseases. The NIH led an interagency group whose task was to identify health risks associated with climate change. The group recently released its report, A Human Health Perspective on Climate Change, which identifies 11 categories of disease and other human health consequences related to climate change; some that are already occurring and others that will occur.

11 Categories of Diseases and Human Health Consequences

1 Asthma, Respiratory Allergies, and Airway Diseases

2 Cancer

3 Cardiovascular Disease and Stroke

4 Foodborne Diseases and Nutrition

5 Heat-Related Morbidity and Mortality

6 Human Developmental Effects

7 Mental Health and Stress-Related Disorders

8 Neurological Diseases and Disorders

9 Vectorborne and Zoonotic Diseases

10 WaterborneDiseases

11 Weather-Related Morbidity and Mortality

The full report describes in detail what is currently known about these conditions, what research needs to be done to better understand the effects of climate change on health, who will be most vulnerable, and what public health efforts will be most beneficial. The report acknowledges that humans have adapted and will continue to adapt to climate changes, and draws attention to the need for additional research and actions that can be taken to minimize if not prevent human suffering in weather related events and tragedies. The report can be viewed in its entirety by clicking the link below.

Following are excerpts taken directly from the report that show only what is already known about the impact of climate change on the 11 categories of diseases and health consequences identified. The excerpts provide a sense of the scope and complexity of climate related health problems, and a basic understanding of some of these diseases and health conditions; what they are, how they are transmitted, and how prevalent they are.

Asthma, Respiratory Allergies, and Airway Diseases


Cardiovascular Disease and Stroke

Foodborne Diseases and Nutrition

Heat-Related Morbidity and Mortality

Human Developmental Effects

Mental Health and Stress Related Disorders

Mental health disorders comprise a broad class of illnesses from mild disorders, such as social phobias and fear of speaking in public, to severe diseases including depression and suicidal ideation. Many mental health disorders can also lead to other chronic diseases and even death. Stress-related disorders derive from abnormal responses to acute or prolonged anxiety, and include diseases such as obsessive-compulsive disorder and post-traumatic stress disorder. It is estimated that 26.2% of Americans over the age of 18 suffer from a diagnosable mental health disorder in a given year; 9.5% suffer from mood disorders, and 6% suffer from serious mental illness. However, mental health is an area of public health that is often a low research priority and one whose impacts on human and societal well being are typically underestimated, both within the United States and globally.

Individuals already vulnerable to mental health disease and stress-related disorders are likely to be at increased risk of exacerbated effects following extreme weather or other climate change events. Prolonged heat and cold events can create chronic stress situations that may initiate or exacerbate health problems in populations already suffering from mental disease and stress-related disorders. In addition, psychotropic drugs interfere with the body’s ability to regulate temperature; individuals being treated with these drugs could be at increased risk of heat-related illness during extreme heat events.

The severity of mental health impacts following an extreme climate event will depend on the degree to which there is sufficient coping and support capacity, both during and following the event. During the recovery period following an extreme event, mental health problems and stress-related disorders can arise from geographic displacement, damage or loss of property, death or injury of loved ones, and the stress involved with recovery efforts. The most common mental health conditions associated with extreme events range from acute traumatic stress to more chronic stress-related conditions such as post-traumatic stress disorder, complicated grief, depression, anxiety disorders, somatic complaints, poor concentration, sleep difficulties, sexual dysfunction, social avoidance, irritability, and drug or alcohol abuse.

The chronic stress-related conditions and disorders resulting from severe weather or other climate change-related events may lead to additional negative health effects. Studies have shown a negative relationship between stress and blood glucose levels, including influence on glycemic control among patients with type 2 diabetes. Evidence has also shown that human response to repeated episodes of acute psychological stress or to chronic psychological stress may result in cardiovascular disease. Although a direct cause and effect relationship has not yet been proven, some research has indicated a link between various psychological factors and an increased risk of developing some forms of cancer, as well as the progression of cancer in those already presenting with the disease.

Neurological Diseases and Disorders

The United States has seen an increasing trend in the prevalence of neurological diseases and deficits. Onset of diseases such as Alzheimer Disease (AD) and Parkinson Disease (PD) is occurring at earlier ages across the population. Environmental factors are suspected of playing a large role in both the onset and severity of these conditions, although there is a gap in our understanding of this role, especially in relation to genetics, aging, and other factors.

While some of these changes in neurological health likely are due to the aging of a large portion of the population, learning disabilities that affect children also are on the rise, and there are indicators that environmental factors may be involved including changes in climate that may exacerbate factors affecting the rates and severity of neurological conditions.

Neurological conditions generally carry high costs in terms of quality of life for both the sufferer and the caregiver and increased healthcare stresses on the economy and the workforce. Factors affected by climate with particular implications for neurological functioning include malnutrition; exposure to hazardous chemicals, bio-toxins, and metals in air, food, and water; and changes in pest management.

Vectorborne and Zoonotic Diseases

Vectorborne and zoonotic diseases (VBZD) are infectious diseases whose transmission cycles involve animal hosts or vectors. Vectorborne diseases are those in which organisms, typically blood-feeding arthropods (insects, ticks, or mites) carry the pathogen from one host to another, generally with amplification (increased virulence) in the vector (for example, malaria). Zoonoses are diseases that can be transmitted from animals to humans by either contact with animals or by vectors that can carry zoonotic pathogens from animals to humans (for example, avian flu).

Both domestic animals and wildlife, including marine mammals, fish, sea turtles, and seabirds may play roles in VBZD transmission by serving as zoonotic reservoirs for human pathogens or as means of interspecies transmission of pathogens. The epidemiology of VBZD in the United States has changed significantly over the past century, and many diseases that previously caused significant illness and death, including malaria, dengue, yellow fever, and murine typhus, are now rarely seen in this country. This dramatic change is a result of intentional programs to control vectors, vaccinate against disease, and detect and treat cases, with additional benefits from improvements in sanitation, development, and environmental modification.

Examples of vector-borne diseases currently prevalent in the United States include Lyme disease and ehrlichiosis, bacterial diseases that are transmitted primarily by ticks. Other important zoonoses in the United States, some of which are also vectorborne, include rabies, Q fever, anthrax, pathogenic E. coli, tularemia, hantavirus pulmonary syndrome, and plague.

Waterborne Diseases

Waterborne diseases are caused by a wide variety of pathogenic microorganisms, biotoxins, and toxic contaminants found in the water we drink, clean with, play in, and are exposed to through other less direct pathways such as cooling systems. Waterborne microorganisms include protozoa that cause cryptosporidiosis, parasites that cause schistosomiasis, bacteria that cause cholera and legionellosis, viruses that cause viral gastroenteritis, amoebas that cause amoebic meningoencephalitis, and algae that cause neurotoxicity.

In the United States, the majority of waterborne disease is gastrointestinal, though waterborne pathogens affect most human organ systems and the epidemiology is dynamic. A recent shift has been seen in waterborne disease outbreaks from gastrointestinal toward respiratory infections such as that caused by Legionella, which lives in cooling ponds and is transmitted through air conditioning systems. In addition to diarrheal disease, waterborne pathogens are implicated in other illnesses with immunologic, neurologic, hematologic, metabolic, pulmonary, ocular, renal and nutritional complications.

Weather-Related Morbidity and Mortality

The United States experiences a variety of extreme weather events ranging from hurricanes and floods to blizzards and drought. Many of these events cause severe infrastructure damage and lead to significant morbidity and mortality. From 1940 to 2005, hurricanes caused approximately 4,300 deaths and flooding caused 7,000 deaths, primarily from injuries and drowning.

Climate change is expected to increase the frequency and intensity of some extreme weather events, including floods, droughts, and heat waves, though how these events will manifest on a regional level is uncertain. The health impacts of these extreme weather events can be severe, and include both direct impacts such as death and mental health effects, and indirect impacts such as population displacement and waterborne disease outbreaks such as the 1993 Milwaukee cryptosporidium outbreak caused by flooding that sickened an estimated 400,000 people.

The populations most at risk from such extreme events also are growing, particularly as a result of increased coastal development, as recent flooding events and hurricanes have shown. Sea-level rise associated with climate change will amplify the threat from storm surge associated with extreme weather events in coastal areas. Other areas, such as the Southwest, are at risk for decreased agricultural productivity due to increased drought and possible compromise of potable water supplies due to flooding from heavy precipitation events.

Given the increased incidence of extreme weather events and the increasing number of people at risk, research in this area is an immediate and significant need. Preparation has a significant impact on outcomes of extreme weather events. Poor preparedness and response to Hurricane Katrina led to increased morbidity and mortality, as well as economic costs associated with recovery, which were estimated to be in excess of $150 billion. By increasing research funding related to extreme weather events, increased preparedness levels could lower costs and minimize morbidity and mortality from future events.

UPDATES: Radiation in Japan

Links from the Harvard Health Publication's Health Blog regarding the radiation risk in Japan.

Curriculum for Faith Based Youth Groups

a six-session curriculum that helps Christian teenagers explore the relationship between their consumption, their faith, and the health of the planet.
a six-session curriculum that helps Christian teenagers explore the relationship between their consumption, their faith, and the health of the planet.

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Comments 42 comments

billyaustindillon profile image

billyaustindillon 6 years ago

Another great hub Kim - I have noticed that Asthma, Respiratory Allergies, and Airway Diseases, a combination of climate change and unchecked industrialization I feel.

kimh039 profile image

kimh039 6 years ago Author

Thanks Billy. I was surprised by some of the indoor pollutants as well. Glad you stopped by.

Deborah Demander profile image

Deborah Demander 6 years ago from First Wyoming, then THE WORLD

Thanks for a well written hub Kim. It was really informative.


kimh039 profile image

kimh039 6 years ago Author

You're very welcome Deborah, and thank you for stopping by to read, rate and comment. I hope you're now well prepared for climate change!

MFB III profile image

MFB III 6 years ago from United States

Ah, you did well Kim, Let's add acid rain which is wreaking havoc daily, plus mercury in the fish so that the "all you can eat fish fries," just might wind up being all you can eat forever, and if mercury is in the fish, what about the predators that eat the fish, is it also in their scat, leeching into the soils all around us? I enjoyed this immensely, far too many folks in this country just want to pretend it's all a sham, when in reality it is a shame, and one day they will realize just how wrong they were when it hits home for them and theirs.~~MFB III

kimh039 profile image

kimh039 6 years ago Author

I would starve at an "all you can eat fish fry!" If that was the only danger, I'd be in good shape. It's hard to get past denial when you think of all the potential harm. It's easier to think it will never happen than to face the fact that it is and it will. I have to admit, until I read this report, I was very skeptical. I think the term global warming was over used, and focused on the environment rather than human health. I also think that the way the information is presented, makes a big difference. If it's another case of the boy who cried wolf, chicken little and the sky is falling, or martians have landed; people are inclined to be skeptical rather than to panic or jump into action. This report is presented as, "Just the facts, ma'am."

vrbmft profile image

vrbmft 6 years ago from Yucaipa, California

Well, I probably do not "worry" enuf about the impact of climate change, altho, I have had a very difficult time getting over a cough and cold this season. Last Sunday I finally got back to my 4 to 6 mile walks. Today marks four days in a row. I have surprised myself by getting out of bed at 5:30 each morning, I feel so much better all over my body. My stress level is so low that I am probably underreacting to the stack of bills due!! So I am hoping if I continue to take good care of myself on a regular basis, including a hefty exercise regimen that I will adapt and maybe grow extra nose hairs to filter out whatever needs filtering and perhaps develop the ability to see in the dark if suddenly we are covered by clouds for longer than usual. There already is a lot of research on Seasonal Affective Disorders, so we know that darkness and light have a daily impact on our mental health or more precisely our neurological functioning. So we are living in an interesting time in history if not frightening! But I prefer to stay with the interesting so I can sleep at night!


kimh039 profile image

kimh039 6 years ago Author

I was wondering where you've been vern! I don't think worrying would help much anyway, and no one needs more anxiety! Here's to healthy adaptations and doing what you can!

Micky Dee profile image

Micky Dee 6 years ago

This is such a great hub Kim. We cannot live without a safe environment. Thank you Dear!

kimh039 profile image

kimh039 6 years ago Author

I want to make sure you've got plenty of clean air to breathe and beautiful places to see on your bike rides! Thanks for stopping by Micky Dee.

vrajavala profile image

vrajavala 6 years ago from Port St. Lucie

I think AGW has been pretty much discredited by the scientific community. I live in Florida, and I must tell you that the cool weather we have been experiencing for several months has been very refreshing.

However, in some parts of the world the cold has been disastrous.

I'm afraid that unscrupulous opportunists, like Al Gore and others are simply seeking to "redistribute the wealth into their own pockets," I'm afraid.

kimh039 profile image

kimh039 6 years ago Author

Thanks for stopping by vrajavala. I think that's what I liked about this report is that it got beyond global warming and focused on climate change and temperature extremes - and the effects on human health through environmental and other changes.

izettl profile image

izettl 6 years ago from The Great Northwest

You made a good connection between climate change and health, but nothing is one dimensional and so cut and dry. A lot has to do with stress, possibly climate change, and so much more. I'm glad I read the hub! I'm a fan.

kimh039 profile image

kimh039 6 years ago Author

I'm glad you did too! Thanks izetti for stopping by. The link, "the story of stuff" provides some insight into other dimensions of the issue, such as human behavior, corporate and government influence, consumerism, economic necessity, etc. The NIH report focused strictly on the connection between climate change and human health....because that's their area of expertise and responsibility. You make a good point about the pros and cons of specialization!

valeriebelew profile image

valeriebelew 6 years ago from Metro Atlanta, GA, USA

Thanks for this hub, kimh. It is definitely well researched, well written, and an excellent contribution. It is scary how destructive humans can be to themselves and other wildlife. This hub is a bookmark keeper. Thanks again. (: v

kimh039 profile image

kimh039 6 years ago Author

My pleasure valerie. It has been a learning process for me too. I added the link about the plastic recycling after the fact.

epigramman profile image

epigramman 6 years ago

I will have climate change and human health problems IF I don't continue to follow your hubs.

kimh039 profile image

kimh039 6 years ago Author

You know what you need to do then! Follow your heart and my hubs........and if you don't, I'll write a hub about you.

romper20 profile image

romper20 6 years ago from California

wow great post Kim,

I think the fact that we are tearing our earth up goes perfect with your hub :)



kimh039 profile image

kimh039 6 years ago Author

Thanks for stopping by to comment romper20. I appreciate it......and I like A+'s.

blackreign2012 profile image

blackreign2012 6 years ago

I say A++++ This hub was very informative. You expressed your thoughts beautifully Great hub ~hugs~ We as a society really need to start taking a more serious look at climate change and the effects not only to the planet but most importantly our health and the health of our children and their children. :)

kimh039 profile image

kimh039 6 years ago Author

The more ++++++'s the better. I think we'll need to make some lifestyle changes.....and most of us don't like that idea! We might do it for the kids though. Thanks for reading, blackreign.

billyaustindillon profile image

billyaustindillon 6 years ago

The context of the hub gets even more relevant when you consider the health dangers from the oil spill in the Gulf. The toxicity alone is frightening.

kimh039 profile image

kimh039 6 years ago Author

....and sickening! Thanks for coming back to post that billyaustindillon....and happy 4th of July to ya.

justmesuzanne profile image

justmesuzanne 6 years ago from Texas

Thanks for a very relevant and interesting HUB!

kimh039 profile image

kimh039 6 years ago Author

Thank you for your interest in it, justmesuzanne!

H P Roychoudhury profile image

H P Roychoudhury 6 years ago from Guwahati, India

It is great hub. The protection of health under all climate is the vital task of human life to survive.

kimh039 profile image

kimh039 6 years ago Author

Thank you HP. I saw a documentary recently about how much plastic is washing up from the ocean onto beaches around the world. The beaches are literally covered with plastic! So sad.

superwags profile image

superwags 6 years ago from UK

Great hub; it scares me that so many people still deny that this is happening! 2010 was the hottest year since records began in 1850. The ten hottest years since 1850 have occurred since 1998! What more evidence do people need?!

One thing to maybe bear in mind when refering to the potential health implications of global warming is that developing countries which are vulnerable to waterborn diseases, crop failiure etc. probably wont be by the time the temperature increases to a point that there will be a significant rise such problems.

i.e. A poor farmer in Bangladesh today can expect to be at least as wealthy as a rich scandinavian by 2100, with all the healthcare it brings. I believe that this is likely to mitigate against problems that could prove disasterous to health in today's global economy.

That said, this is not a reason to ignore the risks!

kimh039 profile image

kimh039 6 years ago Author

thanks superwags. I think it gets harder and harder to know what to believe from the media nowadays. News has become persuasion, opinion and conversion rather than objective reporting. Most of us don't have the specialized knowledge to even begin to debate a topic intelligently, although many people seem to think they do! We need trustworthy news sources that can report objectively on all sides of an issue.

I'm not sure what you mean about a poor Bangladesh farmer being wealthy in 2010. Sounds like an interesting hub though!

Whether we believe in global warming or not, we can still be prepared for extreme climate change and knowledgeable about the health consequences.

Thanks for your comments, superwags!

gajanis786 profile image

gajanis786 6 years ago

Very nice hub and good information.Keep it up.

kimh039 profile image

kimh039 6 years ago Author

Thanks gajanis. That's the plan!

Ann, best treatment for acne specialist 6 years ago

Climate change has been really hard these days. People get sick because of the sudden changes in weather. There's no one to blame but us. It is because we took nature for granted for the past decades and now it's taking a toll on us. There have been storms, floods, snow storms everywhere in the world and it's becoming worse every single time. We have to do something to help prevent it from worsening even more. We need to start taking care of our environment.

kimh039 profile image

kimh039 6 years ago Author

Until recently, I don't think we even considered that we have some responsibility for our environment. That was the job of government and big business. Recycling plastic is pretty routine for most people now, and we're beginning to see efforts to dispose of cell phones properly and to properly discard medications in our medicine cabinets, but we could do more. Thanks for your interest and comment Ann.

kimh039 profile image

kimh039 5 years ago Author

Thanks Sacudas Foo. I'm not sure what fosamax fracture lawsuit has to do with the hub, but I appreciate your taking the time to read and comment. Best regards.

Jokylu profile image

Jokylu 5 years ago from Waratah North, Victoria.

A very informative hub which raises some real issues and worrying questions. I really think you have about 4 hubs of valuable content here. I enjoyed it all and agree with your conclusion. Great hub , I am voting up

kimh039 profile image

kimh039 5 years ago Author

Thank you Jokylu. The main point is the 11 categories of diseases and related health consequences. I added additional links and information along the way. I did do another hub about understanding radiation levels re Japan's radiation crisis. At that time, I added the radiation links here as an addendum. Thanks for reading, commenting and rating, Jokylu. I appreciate it.

kimh039 profile image

kimh039 5 years ago Author

thanks feihu989.

Maggie.L profile image

Maggie.L 5 years ago from UK

A very informative and eye opening hub. Thanks for sharing this important information with us.

kimh039 profile image

kimh039 5 years ago Author

Thank you Maggie.L. My pleasure:)

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Ausseye 5 years ago

A good start to getting a better appreciation of what the human being in us is about to face...good read. Left me with the troublesome thought, are we about to get that virus from hell??? Warm means more places to grow, ahhhhh

just my human phobia!!!

kimh039 profile image

kimh039 5 years ago Author

Thanks for stopping in to read and comment Ausseye. I think the purpose of the information is not so much to frighten or to stir annihilation fears, as to help us prepare, find solutions, and make some good decisions based on the knowledge we have. The report didn't specifically talk about the idea of global warming, but focused on climate change in a more general sense and how climate change affects human health. It identified areas where more research is needed and things public health and safety professionals can do to help minimize or prevent human suffering in case of a weather emergency. I suppose it is possible that the world as we know it can come to a crashing demise, but humans have been adapting to changes since the beginning of time and will continue to adapt. It's possible that humans could become extinct gradually over a period of time due to multiple factors, only one of which is climate change. Anyway. Thanks for your thoughts, Ausseye, but hold the panic button....for now at least.... then again, another black plague....hmm.

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