The Homeless and Adverse Effects of Climate Change

Ramin et al. (2009) studied the considerable effects climate change will continue to have on homeless people. The homeless are the most vulnerable group in developed countries and they have the highest rates of poorly controlled chronic disease, respiratory conditions, and mental illness, which the authors suggest are exacerbated by climate change. Few people have begun to address this issue and more research is required. These scientists are the first to examine the impact on the health of the homeless of increased heat waves, worsening air pollution, intensified severity of floods and storms, and the expanding distribution of West Nile Virus. Due to these changes, the homeless are highly susceptible to higher morbidity and mortality. Leah Kahn
Ramin, B., Svoboda, T. 2009. Health of the Homeless and Climate Change. Journal of Urban Health: Bulletin of the New York Academy of Medicine 86, 654–663.

Approximately five to eight million Americans experienced homelessness within the last five years and their health suffers. Chronic disease severity is typically worse in homeless people because of extreme poverty, delays and limitations in seeking care, non-adherence to therapy, substance abuse, and cognitive impairment. Heat waves negatively affect the health of the homeless as the globe experiences higher minimum and maximum temperatures as well as greater frequency and intensity of heat waves. For example, 2005 was the hottest year on record in North America and in 2003, Europe experienced the hottest summer since 1500, causing 35,000 deaths. Models project a doubling to tripling of mortality in urban areas across the United States. Homeless are at risk because pre-existing psychiatric conditions triple the risk of death due to extreme heat, as do cardiovascular disease, pulmonary disease, advanced age, living alone, being socially isolated, not having air conditioning, alcoholism, using tranquilizers, and cognitive impairment. The heat island effect exacerbates these health problems since a high majority of the homeless live in urban areas.
Air pollution is also severe in urban areas. Ground-level ozone (O3), acid aerosols, particulate matter, and carbon monoxide aggravate chronic lung disease and asthma. O3 is formed by volatile organic compounds (VOCs) and nitrogen oxide (NOx) in sunlight so it peaks in warmer conditions. It is projected that O3 levels will increase by 2–4% with a 2°C temperature rise and 5–10% with a 5°C temperature rise. Air pollution disproportionately impacts people with cardio-respiratory conditions, asthma, and peripheral vascular disease. The homeless have high levels of exposure to outdoor air pollution and are therefore susceptible to climate change-related increases in air pollution.
 With rising temperatures and air pollution comes more severe weather including floods and storms. Floods were the most frequent natural disaster over the past 10 years, killing over 100,000 people. Models predict more floods due to extreme precipitation, and hurricanes are predicted to escalate in size and severity, putting millions of people at risk of drowning, infectious disease outbreaks, and increased incidence of anxiety and depression. Homeless people occupy marginal areas that are more vulnerable to natural disasters but are not included in most disaster planning.
As precipitation heavily increases, so do water-dependent diseases like West Nile Virus that have mosquitos need water as a vector. The virus came to the United States in 1999 and with spring arriving earlier each year, there is an amplification cycle, an influx of human infection. Mosquitoes are most active at night and people sleeping outdoors are the most vulnerable to the Culex species. People with chronic illnesses such as alcoholism and heart disease—which is prevalent in the homeless—have a higher chance of developing meningoencephalitis when infected with West Nile Virus. 

Common Compounds Impairing Semen Quality

In Denmark, young men were studied to examine the lessening quality of semen. Joensen et al. (2009) tested for perfluoroalkyl acids (PFAAs), which are man-made degradation products of polyfluorinated compounds used in industrial and consumer manufactured goods. Such acids are endocrine disruptors which have many damaging affects on the human body by imitating necessary hormones. The scientists used liquid chromatography-tandem mass spectrometry (LC-MS-MS) with electrospray ionization which analyzes mass and physical separation of a complex mixture of chemicals. The ten acids tested were perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorohexane sulfonic acid (PFHxS), perfluoroheptanoic acid (PFHpA), perfluorooctane sulfonamide (PFOSA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnA), perfluorododecanoic acid (PFDoA), and perfluorotridecanoic acid (PFTrA). Joensen et al. discovered that high PFAA levels related to fewer normal sperm and lower sperm concentration. Leah Kahn
Joensen, U., Bossy, R., Lifers, H., Jensen, A. A., Skakkebæk, N. (2009). Do Perfluoroalkyl Compounds Impair Human Semen Quality? Environmental Health Perspectives 117, 923–927.

These compounds are found in common household items such as food packaging, microwave popcorn, waterproof fabric and clothing, and non-stick cookware like Teflon. They are added to materials to make stain protection treatments, flame retardants, and wire coatings, and once in the body, the compounds settle in organs and tissue for several years. PFOA, PFOS, and PFHxS have half-lives in humans of 3.8, 5.4, and 8.5 years, respectively. High serum concentrations of PFAAs are significantly associated with reduced normal spermatozoa — the fully developed sperm cell. Sperm concentration, the number of individual sperm in ejaculate also decreased in men with more PFAA exposure. Total sperm count, sperm concentration multiplied by the volume, was also analyzed and found to be lower. Sperm motility also decreased to a level that less than 60% of observed sperm had forward movement. All four semen analyses must be healthy and normal in order to successfully reproduce, and they were not.

Such analyses were conducted on 105 men with the average age of 19.0 years. Out of the men selected, 53 had high testosterone and 52 had low testosterone. Thawed serum samples were analyzed for levels of testosterone, estradiol (estrogen), sex hormone binding globulin (a protein), luteinizing hormone which is a testosterone producer, follicle-stimulating hormone for regulating reproductive processes and inhibin B (inhibits certain hormones). Some of the analyses had to be adjusted for the effect of ejaculation abstinence period. From these analyses it was found that the three highest levels of concentration were PFOA, PFOS and PFHxS so they were the only compounds included in the final regression analyses.

The Multilateral Implications of Changing Plant Biology

The significant role of plant biology in human health has largely been ignored so Ziska et al. 2009 studied the multiple aspects of altered plant biology due to climate change and the affects it will have on us. They examined aerobiology, contact dermatitis, pharmacology, toxicology, and pesticide use compared to a rise in CO2. Ziska et al. discovered substantial and highly impactful links between those factos and human health.  Increased CO2 stimulates plant growth generally, and that extends to enhancing the aerobiology of ragweed, loblolly pine, and other weeds. A greater food supply could result in an abundance of animal disease vectors. Plants with skin irritants causing contact dermatitis are increasing in response to more CO2, and some plants are becoming toxic to humans as they absorb carcinogens during growth. Plants are essential to medicine even as some develop toxic characteristics. At least one quarter of all pharmaceuticals contain plant extract and less than 1% of plant species have been studied for their pharmaceutical use. The lack of water and increasing temperatures will negatively impact the flowering state of plant growth. A rise in petrochemicals will impact animals and humans as the chemicals enter the environment.   Leah Kahn
Ziska, L., Epstein, P., and Schelsinger, W. 2009. Rising CO2, Climate Change, and Public Health: Exploring the links to Plant Biology. Environmental Health Perspectives 117, 155–159.

The intentions of this study were to elucidate the role of plant biology on nutrition and the impact of climate change on plant growth. Plants have always held a key role in healing. A large variety of plants provides diversity in the development of existing and new metabolites in pharmacology. For example, codeine, a common analgesic, comes from the Iranian poppy. The World Health Organization (WHO) reported that more than 3.5 billion people depend on plants as a component of their primary health care.
Ziska et al. also studied unusual ways that our food supply will be affected. Blooming is the most thermal-sensitive stage of plant growth. Exposure to higher temperatures during reproduction will negatively affect pollen viability, fertilization, and fruit formation. Warmer temperatures and additional CO2 may extend growth periods however; this could further exacerbate reproductive sterility because of restricted transpirational cooling. These scientists predict that food crops will become starchier and protein-deficient, and digestibility will decline as is the case in paddy rice. There has also been a reduction in flour protein concentration and its optimum mixing time. As plant growth increases with rising CO2, the spread of human diseases will climb. Plants are not typically disease vectors but rodents and mosquitoes rely on plants as principle food. Since plant growth is increasing, Ziska et al. predict that animal vectors will multiply.
To control these rapidly growing plants, more pesticides, herbicides, and fungicides will be used. The concern is whether these chemicals will be able to limit and control the effects of climate forcing and CO2-induced changes in public health and plant biology. Due to similar studies of the Canada thistle, there is a rising concern of decreased chemical efficacy to control weeds. Greater use of petrochemicals risks human and animal health.

Plant-based respiratory allergies are a common health problem causing symptoms like sneezing, wheezing, nasal polyps, asthma, and pulmonary disease. Pollen is being produced in larger quantities and earlier in the season due to climate forcing of phenology—the study of animal and plant life cycles. A 35-year study of birch trees indicates earlier spring floral initiation and pollen release with anthropogenic warming. Also, diesel particles in the air help push allergens deep into airways and lungs. Data cited in this paper demonstrate that climate forcing and rising CO2 have a direct impact on increased pollen, spore production, and human exposure.

The future of agriculture, water and human health in Poland

Existing climate projection data from the ENSEMBLES Project of the European Union was applied to patterns of extreme weather and its impact on Poland.  The project scientists studied many changes, including forest degradation, precipitation, extreme weather, and vegetation period — the time between sown seeds and first signs of fruit — across the European continent. In order to closely examine Poland and project its climatic future, the authors extrapolated the data from ENSEMBLES across Europe to Poland.  Agriculture, water resources and human health sectors were studied based on multiple aspects of climate change to determine the transforming risks to those sectors.  The result was detrimentally warmer summers and wetter winters, which shrink the vegetation period of crops as well as increases mortality of the aging human population in Poland.  The study also demonstrated that evapotranspiration will greatly exceed precipitation and therefore deplete water storage in the soils. — Leah Kahn
Szwed M., Karg G., Pinskwar I., Radziejewski M., Graczyk D., Kedziora A., and Kundzewicz Z. W., 2010. Climate change and its effect on agriculture, water resources and human health sectors in Poland. Nat. Hazards Earth Syst. Sci. 10, 1725–1737.

            Multi–model ensemble climate projections were used to assess the effects of climate change in Poland.  The ENSEMBLES Project studied global change and ecosystems from 2004–2009.  These data were evaluated by comparing two simulations a century apart over a 30–year period.  The three sectors were analyzed from 1961–1990 and 2061–2090.  The data from 1961 to 1990 were applied to the future to predict the coming impacts.  Some of the changes are thought to be advantageous and others disadvantageous, but these sectors are likely to be adversely affected in Poland.  According to the Intergovernmental Panel on Climate Change, the next two decades will bring a global warming of about 0.2°C per decade.  Observations confirm that cold days have become warmer and more frequent and this trend is likely to continue.  The following five characteristics of a 30–year interval were used in this study: the number of consecutive days with a high of over 35˚C and a low of less than 25˚C, the number of consecutive days with a heat index (HI) above 36, the record temperature during those 30 years, length of the vegetation period, and the number of days with little to no rainfall.  Scientist examined how many days reached above 95˚F, which is very warm for Poland located in northern Europe.  An HI is based on what temperature actually feels like to a human.  The index comes from a temperature above 35˚C and humidity higher than 30%.  The vegetation period is a window of time during which, the temperature is consistent enough for crops to begin to grow. 
            The first indication of climate change was found in the examination of maximum and minimum temperatures.  The southeast of Poland was hardest hit by the rise in consecutive days over 35˚C.  It is projected to experience 14–16 days of extreme heat at a time.
            Overall, agriculture in northern Europe has been limited by temperature while southern Europe has been restricted by water.  Projections for the future are positive for parts of Poland because it releases the temperature restriction on agriculture. Although, southern parts of Poland currently struggle with water storage will grapple with limited water more and more because there will be a decrease in rainfall and an increase in temperature.   The majority of Poland will have less than five days of precipitation above 0.5 mm as expressed in the data.
            Most of Poland will experience an increased vegetation period of between 30 to 40 days according to the authors.  There are a few isolated locations where the period will lower to between 20 and 30 days.  Crops grown in winter and summer experience three stages of growth, which respond to higher temperatures.  The changes in crop yields of potatoes and corn were measured based on precipitation–yield field experience of the authors.  They discovered that crop yield is dependent on water during the 30 days before ears of corn appear and between July and August for productive potato plants.  The authors demonstrate that there will be a decrease in crop yield of 2.175 tons per hectare of potatoes and 0.539 t/ha of wheat.  In comparison, the average yield between 1961–1990 was 19.18 t/ha for potatoes and 3.53 t/ha for wheat. 
            As agriculture is vitally dependent on water, these scientists researched the water budget in Poland.  The water budget is the gap between rainfall and the evaporation of that rain from the surface of the earth.  Scientists used a mathematical formula to test this during summer months.  At present, evapotranspiration surpasses precipitation during the summer so water storage in bodies of water, soil and ground water decreases.  The formula projects more severe summer water shortage.  Evapotranspiration is based on the amount of energy required to turn water into vapor and if there is more water in the air than on the surface, the water balance dives into negative values, increasing the water shortfall.  The authors used a more extensive formula involving energy categories to calculate the probability of a negative water imbalance.  The probability went from .84 during the reference period to .96 in the future.  That is roughly –50mm of water available whereas it was at about 32mm of water on the surface during the reference interval.
            Two energy ratios were calculated to measure evapotranspiration; Energy Ratio 1 (ER1) illustrated the actual degree of drought; the higher the value of ER1 the worse the drought.  Energy Ratio 2 (ER2) indicates the probable degree of drought by showing how much water is needed to take full advantage of the agricultural environment.  The two datasets demonstrate that the drought will increase by 100%.  A spatial map of each dataset illustrates that there are about 27 cells with an ER1 value of less than one during the observation period.  There will be only 10 cells with a value less than one in the future period.  The ratio is projected to increase to about 1.5 in central Poland.  This means that rainfall will only make up for half of the water evapotranspiration is taking away.
            These sectors both influence the third sector of the study, human health.  The polish population is rapidly aging.  More heat waves are projected and heat related illnesses are very common when extreme heat lasts more than two days.  The coming heat waves will last between 14 and 16 days.  The extreme weather becomes fatal when the air does not cool down at night.  If humidity is also high, the body cannot cool itself off effectively using the evaporation of sweat.  According to this paper, both numbers of Poles older than 65 years are going to increase, days above 32˚C. This paper used the proposed threshold of HI=36, and also studied senior–discomfort days by using an index of HI=32.  The number of senior–discomfort days is projected to increase 8 times over in the next 100 years.
            The most successful response to these findings is to adapt.  The agricultural sector requires practices such as crop rotation, advanced sowing dates due to vegetation periods and the introduction of drought resistant strains.  The water usage sector needs more water storage such as manmade lakes, mulching fields, and groundwater aquifers.  To prevent a decline in human health, people must have heat warning systems, air conditioning such as swamp coolers and stone buildings, and a strong education in heat related illness prevention.  This study projects the future of Poland and its inhabitants based on a successful European climate change model.  Poland is experiencing less water and drier soils and therefore producing fewer crop yields.  Without staples and a water deficit, human health is impacted.  Those most influenced by it are the aging population of Poland.

Global Climate Change and Implications for Disease Emergence

Slenning (2010) examines current research and theories on the relationship between global climate change (GCC) and an increase in human and animal diseases.  He compared research from 38 different studies and decided that the biological response to GCC will be an altered balance between disease agents, vectors, and hosts to increase disease incidence.  Weather will become more variable and extreme which will destabilize ecosystems, forcing plants and animals to migrate to less habitable environments.  GCC is leading towards ecological tipping points, which, in the past, have taken millennia to recover from.  Increased temperatures are causing some synergies to become stronger and therefore spread invasive species and diseases across the globe.— Leah Kahn
Slenning, B. D., 2010.  Global Climate Change and Implications for Disease Emergence. Veterinary Pathology 47, 28–33.

            The public has struggled to understand climate change; not its definition but the sense of urgency required to respond to it.  It is difficult to grasp the gravity of the issue when there are few examples of what will result from climate change.  People want proof but many are not as of yet convinced because of the lack of physical evidence they can see.  Barrett D. Slenning studied the facts versus the theories of climate change and discovered what information is still needed to prove those theories and thoroughly convince the public.
            Vector-borne diseases are his main concern.  A vector-borne disease is a three-step process.  The disease starts as a pathogen and is picked up from a mammal by an arthropod, usually a tick or mosquito, and then is transferred to a human host through blood.  For example, ticks carry lyme disease because they feed on field mice.  It is often believed that ticks are just natural carries of the disease but they actually get it from another source.  As larger animals become less common due to deforestation, ticks more often feed on mice so the rate of lyme disease has increased.
            There are 35 years of solid proof of climate change.  The earth’s land mass has already experienced between .2 and 1 ºC increase in temperature which is basically the difference between two geological eras.  To make matters worse, Arctic temperatures have increased at twice the global rate.  Herbicides are less effective on invasive species thriving on CO2, so crops are less successful. 
            Ecosystems are changing so our relationships to them must change.  Health events like African Rift Valley fever outbreaks are driven by weather over the Indian Ocean several months before.  Warmer waters allow vectors like bluetongue and hantavirus to survive in Europe, which harms fish and human populations.  Water-borne disease flourish in the heavy rainfall certain regions like Pakistan are experiencing.  The effects of GCC are unequally distributed across the globe.
            Where the public grows frustrated is the lack of knowledge of how each disease is going to respond.  Due to extensive research, scientists have a strong idea of the several different ways diseases will react but cannot predict the precise outcome of each pathogen.  As cycles are altered, some pathogens may not survive but others will spread like wildfire.  There must be quick research done of domesticated and wildlife animals to better understand the impact of diseases.  The type of research being done must change.  Research must be performed on models that offer assumptions that can scale or transfer to other regions so conclusions can be more widely applied.

Small Mammal Response to Climate Change

            Research on the period of climate change between the Pleistocene and Holocene eras has revealed that small mammals are not as resilient to changes in climate as had previously been assumed. The data suggest that rapidly changing climates negatively influence the richness and evenness of small mammals living in an ecosystem.  It is possible that these past trends can be used to predict animal populations’ survival response to our currently warming climate.  Blois et al. (2010) examined northern California’s small mammal populations during a warming climate and they concluded that small mammals have a direct relation to climate change which decreases their populations. — Leah Kahn
Blois J., McGuire J., Hadly E., 2010. Small mammal diversity loss in response to late-Pleistocene climatic change. Nature 771–774

            The species groupings of animals living in communities are shaped and influenced in numerous ways. This paper focuses on how the change from a glacial to interglacial climate influenced the survival of all species of small mammals.  The shift from the Pleistocene epoch to the Holocene epoch took place between 15,000 and 12,000 years ago, and significantly warmed the planet.  The average global temperature during the Pleistocene was 5 ºC which warmed to 7 ºC during the Holocene. The researchers excavated small mammal fossils surrounding the Samwell Cave Popcorn Dome in northern California.  They studied the remains of two pocket gopher species, as well as mountain beavers, ground squirrels, chipmunks and voles.  Significant loss from local communities is a pattern mirrored across North America during glacial-interglacial change, and the trends of fauna observed at this northern California cave can be used to broadly represent this diversity loss.
            Scientists were able to determine how old the fossils were by using radiocarbon dating and ancient DNA testing from specimens’ molars.  They examined the evenness of species composition throughout the shift to a warmer climate.  Evenness is a way to measure the balance of individuals.  For example, an ecosystem with 40 dogs and 42 foxes is much more even than one with 40 dogs and 100 foxes.  This is neither good nor bad but it allows scientists to more closely examine changes in taxa fitness.  Richness fell from 12 to 8 taxa.  Richness is simply the number of different kinds of animals in any given region or ecosystem.  The Amazon rainforest is, for example, much richer in species than the Southern California desert.  Blois et al. analyzed the change in evenness and richness during the rapidly warming climate. The data demonstrate a significant decline in species evenness and richness as the global temperature warms.
This aids our understanding of how small mammals may react to our current swiftly warming climate.  This decline in evenness and richness may occur in modern small mammal communities.  Small mammals are often viewed as unaffected and impervious to altered ecosystems due to their fast growth rate and high population densities.  However, these data illustrate that they are at risk for diversity loss.  This is most likely due to small mammals being directly affected by climate change.  Many animals in the region preferred cooler forests but small mammals were found unlikely to migrate to cooler regions and therefore became locally extinct.  Trends across North America confirm this lack of migration.  Some species may not have been able to keep up with climate change evolutionarily.
An alternative theory which could explain the changes in the small animal population include the extinction of megafauna, which may have altered predation and vegetation patterns.  Human impact is also unlikely because humans did not populate the region until about 3,000 years later.  There is currently a lack of support for either of these two theories.  The data in this study strongly suggest that a quickly warming climate will negatively impact the diversity of small animal populations.