Climate - MSc Epidemiology

Transcription

Health Effects of Weather
and Climate
Lecture
Dr. Alexandra Schneider
Neuherberg, January 28, 2016
Environmental Factors that May
Affect Health
Das Bild k ann zurzeit nicht angezeigt werden.
Taken from „Basic Epidemiology“
by R. Beaglehole and R. Bonita
Individual Characteristics that Modify
the Effect of Environmental Factors
Taken from „Basic Epidemiology“
by R. Beaglehole and R. Bonita
Basics in Meteorology
Layers of the Atmosphere
Troposphere:
- Weather processes
- 75-90% of atmospheric
mass (and most of H2O)
- Temperature decrease
about 6.5°C / km
Tropopause:
- 8-10km height
Stratosphere:
- Includes about 90% of
total ozone (ozone
layer in a height of
about 15-20 km)
- Temperature increases
with height
Mesosphere:
- 50-80km height
- Temperatur and
barometric pressure
decrease dramatically
- UV light not filtered by
ozone layer
Thermosphere:
- Up to 250km height
- Still N2 and O2 are main
components
Exosphere:
- Transition zone from
atmosphere to outer
space
Role of the Atmosphere
Protection from adverse radiation from space (UV, X-ray)
But: Atmosphere lets transit radiation from sun that is necessary
for life on earth
Heat-balance between night and day (protection from quick
cooling)
Leads to an average surface temperature of +15°C and not -18°C
Transport of energy (sensible and latent heat) and water vapor
from equator to north and south
Main N2-storage (necessary for plants)
Reservoir for CO2 and O2
Distribution and reduction of natural and anthropogenic emissions
Protection from meteoroids (which spoil due to friction when
entering atmosphere)
Elements of the Atmosphere
Nitrogen (N2): 78%
Oxygen (O2): 21%
Argon (Ar): 0.9%
Carbon dioxide (CO2): 0.04% (increasing!)
Rest: helium (He), krypton (Kr), xenon (Xe), methan (CH4), carbon
monoxide (CO), hydrogen (H2), nitrous oxide (N2O), ozone (O3)
Key Terms for Literature Reading (1)
Weather:
Atmospheric condition in a specific place at a specific time
Climate:
The average state of the atmosphere and the underlying land or water in
a specific region over a specific time-scale.
Climate variability:
Variability in the mean state or other statistical measures (such as
standard deviations or the occurrence of extremes) of the climate on all
temporal or spatial scales beyond that of individual weather events.
Climate change:
A statistical significant variation in either the mean state of the climate or
in its measureable variability, persisting for an extended period (typically
decades or longer).
Extreme weather events:
Events that are rare within their statistical reference distribution at a
particular place (e.g. heat wave, cold spell, drought, hurricane, …).
Key Terms for Literature Reading (2)
Heatwave:
A heatwave is defined as a prolonged period of unusually hot weather but a
standardized definition has not been agreed upon and different definitions are
currently used to evaluate the impact on health.
Climate change mitigation:
An anthropogenic intervention to reduce the sources or enhance the sinks of
greenhouse gases.
Adaptation:
Strategies, policies and measures undertaken now and in the future to reduce
potential adverse impacts of climate change.
Vulnerability:
The degree to which individuals and systems are susceptible to or unable to
cope with the adverse effects of climate change, including climate variability
and extremes.
Scenario:
A description of a set of conditions, either now or, plausibly, in the future.
Elements of Daily Weather (1)
Barometric pressure:
Most important element of synoptic meteorology
Weight of the column of air (from surface of earth to upper
limit of atmosphere) perpendicular on the area of 1 m²
At sea level: 1013.25 hPa (also called: 1 atm)
(1 m³ of air has approximately the mass of 1 kg → at sea
level: air mass >10 tons per 1 m²)
Barometric pressure can be split into two partial pressures:
- Water vapor pressure, ranging from 0 hPa to a temperaturedependent maximum (=saturation)
- Pressure of the remaining dry air.
Unit: 1 N/m² = 1 Pa; 1 hPa=10² Pa=1 mbar
Air temperature:
It characterizes the thermal situation in the atmosphere and is a
measure for the kinetic energy of the gas molecules.
There exist different scales for measuring air temperature:
- Celsius (used all over the world – except for U.S.) with
fix points 0 °C = melting ice and 100 °C = boiling
water
- Kelvin (0 K= absolute null =-273.15 °C) mainly used in science
- Fahrenheit (used in the U.S. only) with fix points 0° F= -32 °C
= lowest measured temperature in Danzig and
100° F=37.8 °C = human body temperature)
Dew point temperature:
The temperature at which the air with current humidity is
saturated with humidity (100% relative humidity)
Unit: 1 °C
Apparent temperature:
Virtual temperature based on the fact that air temperature feels
different with different humidity levels (due to latent heat stored in
water vapor): Tapp=-2.653+0.994*Tair+0.0153*Tdew²
(Steadman 1979; Kalkstein and Valimont 1986)
Similar concepts: PET, UTCI (*)
Absolute humidity:
Mass of water vapor contained in air
Unit: 1 g/m³
Relative humidity:
Ratio of actual water vapor pressure and maximal possible water vapor pressure
at the given temperature (saturation)
Unit: 1 % (100 % = actual water vapor pressure has reached saturation point)
(*) PET: physiological equivalent temperature
UTCI: universal thermal climate index
Wind:
Mostly horizontal movement of air due to a balance of three
forces:
- Pressure gradient force
- Coriolis force (due to earth rotation)
- Friction force
Vector given by wind direction (36 directions on compass card:
N=360°, East=90°, South=180° and West=270°) and wind speed
(in m/s or km/h)
Wind-force can be given in Beaufort-scale (1-12) which is based on
damages that different wind-speeds can cause.
Precipitation:
Different forms of precipitation (rain, snow, hail etc.)
Unit: 1mm (per 1m²) = equivalent to 1 liter of water
If duration is measured, too, then precipitation height and duration
together give precipitation intensity.
Radiation:
The sun is the force of the atmospheric circulation.
Sunlight measurements: intensity and duration.
From the sun we get the full spectrum of wavelength, but 96% are
between 0.3 and 3 µm:
- UV(-A, -B, -C)-light with 0.20-0.35 µm
- Visible light (violet-blue-green-yellow-orange-red) with 0.35-0.78 µm
- Some IR-light with 0.78-1000 µm.
Clouds and aerosol (gases and particles, ozone) can absorb, scatter or
reflect the sunlight.
The earth is reached by 50% of the sun‘s radiation and can then emit
IR-light which is also absorbed, scattered or reflected by clouds and
aerosol (H2, CO2).
Annual and Global Mean Energy Balance
Intergovernmental Panel on Climate Change (IPCC) 2007
The Greenhouse Effect
1/3 of solar radiation is reflected
back to space and 2/3 are absorbed
by the earth‘s surface. To balance
the absorbed incoming energy, the
earth must radiate the same amount
back to space (longer wavelength
than solar radiation as earth is colder).
Much of this thermal radiation is
absorbed by clouds and gases.
The natural greenhouse effect
makes life as we know possible.
Burning fossil fuel and clearing
forests have intensified the natural
greenhouse effect causing global
warming.
Problem: Clouds are effective in
reflecting solar radiation but also in
absorbing infrared radiation.
Water vapor is the most important greenhouse gas and
carbon dioxide is the second-most important one.
Positive feedback: warmer atmosphere – more water
vapor – more warming – additional water vapor - …
Type, location, water content, cloud
altitude, particle size, shape and
lifetime affect the degree to which
clouds warm or cool the earth.
IPCC 2007
Air masses (1)
Description:
A body of air with more or less uniform characteristic is an
air mass.
Air masses are moved around the globe by winds and create
our weather. When an air mass arrives in a region, it can
displace the existing air mass.
The character of air masses varies greatly. Over
continents air mass temperature depends greatly on the
time of the year (winter: cold, summer: warm). Oceans, on
the other hand, vary little in temperature through the year
and maritime winds from this source region are humid and
warm.
An air mass mainly shows characteristics from its source
region but can of course change by passing over other
regions.
Air masses (2)
Description:
The boundaries (vague and diffuse)
between air masses are called fronts:
when cold air replaces warm air across
a region a cold front has moved through;
a warm front occurs when warm air rides
over an existing cold air mass.
The interaction of warm and cold air
masses may produce low-pressure
systems that give rise to unsettled
weather, particularly in middle latitudes.
Surface weather chart
Rotation of High- and Low-Pressure Area
anti-cyclonal
cyclonal
T
warm front
Balance between:
- Pressure gradient force
(from high to low),
- Coriolis force (due to earth
rotation: deflection of air to the
right on Northern hemisphere),
- Centrifugal force
- Friction force.
cold front
⇒ High-pressure areas rotate clockwise
(anti-cyclonal)
⇒ Low-pressure areas rotate counterclockwise
(cyclonal)
Geo Special 2/2004 and Schuh 1995
Low-Pressure Area
- Warm Front Warm air weighs less than cold air
cold air
Schuh 1995
Low-Pressure Area
- Warm Front: Typical Clouds -
Cirrus
Stratus
Cirrostratus
Photos: Mühr 1995, www.wetteratlas.de
Low-Pressure Area
- Cold Front Cold air weighs more than warm air
warm air
Schuh 1995
Low-Pressure Area
- Cold Front: Typical Clouds -
Occlusion
Cumulus
nimbus
Photos: Mühr 1995, www.wetteratlas.de
Special Weather Events
- Föhn -
Föhn situation:
Wind from the South
(Mediterranian air) hits
the Alps directly and
perpendicularly.
Schuh 1995
Föhn
Roth 1990
Warm, dry and frequently very stormy downslope wind on
the lee side (side sheltered from the wind) of mountains.
(lat. flavonius: mild west wind)
Föhn-Examples
„Föhn-wall“
Föhn-wall at peak of Zugspitze,
View to the south, 27.01.2006, 8:00
Munich with Föhn
.
Föhn in Theory
.
Schuh 1995
Föhn
- „Föhnfische“, Cumulus lenticularis -
Roth 1990
.
Föhn
Exists at all high mountains in the world!
Height of mountain range important for intensity.
The Alps: North föhn and South föhn
German Mittelgebirge (Erzgebirge)
Rocky Mountains: East side (Chinook, Santa
Ana)
Atlas Mountains (Schirokko; not
Mediterranean Sea-Schirokko: warm and
humid!)
High Tatra (Halny)
French Massif Central (Aspr)
The Andes (Puelche, Zonda)
Newseeland Alps (Canterbury Northwester)
Skanden (Scandinavia, up to 2400 m height
⇒ Föhn at coast of German Baltic Sea)
Special Weather Events
- Sultriness, Thunderstorm, Inversion Sultriness („Schwüle“):
Combination of moderate to high temperatures and moderate to high humidity
Cutpoint for sultriness defined differently by different authors: Wikipedia uses a cutpoint
of absolute humidity of 13.5 g/m³ (leads to sultriness from 16°C with 99% relative
humidity to 37°C with 30% relative humidity)
Thunderstorm (also known as electrical storm, lightning storm):
Form of weather characterized by the presence of lightning and its effect: thunder.
Usually accompanied by heavy rain and sometimes snow, hail, or no precipitation at all.
Thunderstorms may line up in a series, and strong or severe thunderstorms may rotate.
(Temperature-) Inversion:
Deviation from the normal change of an atmospheric property with altitude: i.e. an
increase in temperature with height (results e.g. in freezing rain in cold climates)
Can suppress convection by acting as a "cap".
Can lead to pollution such as smog being trapped close to the ground (with possible
adverse effects on health)
Weather Sensitivity
Evidence (1)
Associations between weather and the following health
problems have been shown so far:
General well-being
Pain intensity
- Chronic diseases of the musculoskeletal system
- Migraine
(Cardio-)vascular diseases (e.g. myocardial infarction, stroke)
Respiratory diseases
Depression and suicide
Emergency calls
Traffic accidents
Birth, labor
Premature deaths
Evidence (2)
The following weather phenomena can act as triggers or
amplifiers for the mentioned disorders:
Weather change
Cold (especially in winter)
Heat
Sultriness
Inversions and smog
Föhn
Thunderstorms
General deviations from the normal course of the year
Air pollutants (see lectures Dr. Wolf (chronic), Dr. Pickford (acute))
The Syndrom of Weather Sensitivity (1)
- Who is Susceptible? Reacting to weather („Wetterreagierende“):
Everybody – normal physiological response to atmospheric stimuli in the
sense of an adaptive procedure.
This should happen automatically without producing any stress except for
maybe slight mood changes or changes in the general well-being without
specific reasons.
Being sensitive to weather („Wetterfühlige“):
Ca. 50 % of the population – reduced threshold for stimuli of the autonomic
nerous system, regular impact of weather on general well-being and life
quality.
With increasing age between 30 and 60 years the percentage of concerned
persons is increasing: over 60 years of age the percentage is already 68%.
More women than men report to be weather sensitive.
It leads to an overreaction that can produce symptoms such as tiredness,
headache, concentration problems or reduced productive efficiency.
- Who is Susceptible? Being susceptible to weather („Wetterempfindliche“):
Ca. 10% of the population – strong burden of overreactivity to weather.
Mostly people who became so extremely over sensitive due to existing chronic
diseases, surgery procedures, severe acute diseases or accidents.
Symptoms of existing diseases are intensified, such as migraine attacks,
asthma attacks, angina pectoris and pains through scars or amputation
(phantom pain).
These people need to see their physician on such days.
Being pre-sensitive to weather („Vorfühlige“):
Ca. 50 % of the people who are weather sensitive – these people feel the
coming weather change before the weather is really changing (a couple of
hours up to 3 days!).
It is a very intensive form of weather reaction and is pronounced in patients
with rheumatic diseases, scar pains and cardiovascular diseases.
The frequency of this form of weather sensitivity increases with age,
especially in women entering the menopause.
- Who is Susceptible? Myocardial infarction patients suffer more from weather
sensitivity than the average population.
The Augsburg Myocardial Infarction Registry (Helmholtz
Zentrum München) has published in 1998 that 2 - 10 years
after the myocardial infarction has occurred, 72% of women
and 46% of men experience weather sensitivity as an extreme
problem (Ärztezeitung).
Also patients up to 5 years after a bypass-surgery feel very
weather sensitive (Herlitz et al., 2001).
Cardiac events increase on average 20-40% in the winter
months. There is a clear winter-peak in coronary heart disease
as well as in mortality due to chronic heart failure (Pell et al.
1999).
Symptoms of Weather Sensitivity
Exhaustion / abnormal fatigue
Nervousness
Bad mood / Depressive state
More mistakes at work
Aversion to work / do anything
Increased forgetfulness
Headache
Flickering in front of eyes
Sleeping disorders
Dizziness
Concentration problems
Heart problems
In general no clear symptoms – more symptoms of the general well-being, but also
intensification of existing diseases (headache, migraine, rheumatic diaseases, cardiovascular
diseases).
Comorbidity and prevalence of chronic problems of the vascular system is clearly higher in
persons who suffer from weather sensitivity (Höppe 2002).
Socio-economic impact:
1/3 of the weather sensitive people are not able to fulfil their daily work due to their weatherrelated problems. Employed weather sensitive people are not able to go to work on 4-10 days
per year (Höppe et al. 2002). This means a loss of 18 Mio. work days and costs several 1000 Mio. €.
In addition, there are costs for the health system due to costs of the general practitioners,
therapeutic treatments, medication and treatments at health resorts.
Possible Mechanisms of Weather
Sensitivity
Lack of training of the whole body
Adaptive capability is over-demanded when trying to adapt to
changing weather situations: the body has a reduced adaptive
capacity to react to external changes.
Causal factors for this reduced adaptive capacity:
- Lack of physical activity
- Lack of exposure to thermal stimuli
Possible Therapy
Training for the whole body
Training of thermoregulation
• Give thermal stimuli: shower cold, shower cold-warm-cold,
Kneipp-hydrotherapy, sauna, move often in fresh air: walking,
hiking, running outside
• „Active“ exposure to outside weather: Go outside every day
despite the current weather situation: „cool regimen“ (slight cold
has a trainings effect even without sports!). This leads to cold
(but also heat) adaptation. But: use appropiate clothing: gloves,
cap, jacket, protect triangle nose-mouth-throat when it‘s really
cold! Don‘t do much sports when it‘s really hot and avoid hottest
hours!
Moderate endurance capacity training
• Movement therapy („Bewegungstherapie“)
• Sports, if possible outside: biking, gymnastics, skiing, running,
swimming in cool (not too cold) water, …
UV-radiation and Vitamin D (1)
Vitamin D belongs to a group of hormones involved in calcium metabolism
and bone mineralization.
Principal source: cutaneous synthesis after exposure to UVB (smaller
contributions coming from diet and supplementation).
Best indicator of vitamin D status: concentration of serum 25-hydroxyvitamin
D (25(OH)D) in blood.
KORA F4-participants ( N=3061)
Richter et al. 2014
UV-radiation and Vitamin D (2)
Richter et al. 2014
UV-radiation: pro and con
Vitamin D = preventive agent for many chronic diseases:
e.g. frailty (Pabst et al. 2015), asthma (Checkley et al. 2015), type 2 diabetes
(Thorand et al. 2011) or cardiovascular disease mortality (Durup et al. 2015).
The biology of humans is adapted to a stable vitamin D level, as it is only
possible at low latitudes with continuous UVB-exposure and consequently
high cutaneous vitamin D production throughout the year (Vieth 2011).
UVA (and UVB): responsible for aging of skin.
UVB: sun burns, immune suppression, main risk factor for skin cancer
(Greinert et al. 2008), risk factor for cataract (Shoham et al. 2008).
Skin cancer in Germany: incidence = 234.000 in 2013 (Katalinic 2013), most
frequent cancer-type in Germany.
Reasons might be: changing UVB-intensity due to climate change (Greinert
et al. 2008) + changing exposure behaviour during leisure times by
population (Völter-Mahlknecht et al. 2004).
Effects of Air Temperature:
- Decreasing / increasing temperature
- Cold spells / heatwaves
Results from selected projects
Evidence and Facts about Cold Effects
In Western Europe up to 250.000 excess deaths due to cold weather
(Keatinge 1998)
Increase of cardiovascular events (including mortality) in winter months
(Yarnell et al. 1991; Barnett et al. 2005; Curwen and Devis 1988)
Increased blood pressure (up to 8 mmHg) in winter (Alpérovitch et al. 2009)
Sudden decrease in temperature, for example strong weather change during westflow weather situations („Westwetterlage“) with a sudden cold spell:
⇒ Increase in risk with a 10 °C decrease for:
• First myocardial infarction: 11 %
• Re-infarktion: 26 %
• Fatal infarction: 11 % (MONICA-Projekt, WHO 1999: Danet et al. 1999)
U-shaped association between coronary heart disease and air temperature:
- Thermal optimum between 15 and 20 °C (lowest mortality)
- Increase in both directions of the thermal optimum:
On the cold side increase of event rate 1 % per 1 °C temperature decrease
(Nayha 2002)
Cold effects last up to 4 weeks! (Braga et al. 2002; Goodman et al. 2004)
The February 2012
Cold Spell and
Mortality in Italy
Analyzed cities:
Turin, Genoa,
Milan, Bologna,
Trieste, Rome
Reference period:
2008 - 2011
de´Donato et al. 2013
Evidence and Facts about Heat Effects
Warm side of the U-shaped association: Geographic variability is more pronounced, but
the increase is about 4 % in coronary heart disease per 1 °C temperature increase above 25 °C
(Nayha, 2002).
So deaths related to hot weather cannot only occur during heat waves!
Heat wave of 2003: More than 30.000 (Kosatsky 2005) to 70.000 (Robine et al. 2008) excess
deaths all over Europe – particularly in France (see next slide!)
Heat wave effects occur after a very short time lag (same day or one day lag).
(Basu and Samet 2002)
Heat effects very pronounced in respiratory morbidity and mortality.
(Huynen et al. 2001; Hajat et al. 2002; Michelozzi et al. 2008)
Effect modifiers: Age, disease status, gender, socio-economic status, behavior, air condition,
prevention measures (heat warning systems)
(Donaldson et al. 2001; Healy 2003; O‘Neill et al. 2003; Michelozzi et al. 2004; Pascal et al. 2006; MedinaRamon and Schwartz 2007; Stafoggia et al. 2006)
„Harvesting effect“ or mortality displacement: Effects only in elderly or weakened
persons, so that death is simply being brought forward by a few days or weeks.
Reasonable to assume that an increase in mortality may be followed by a compensatory
decline in the number of deaths a few days later.
During that time the pool of susceptible persons slowly fills up again. However, this only
explains small percentage of observed increase in mortality. (Le Tertre et al. 2006)
The 2003 Heatwave and Mortality in Paris, France
Vandentorren et al. 2004
Heat and ER-visits in North Carolina 2007/2008
Lippmann et al. 2013
Results from a European Project:
PHEWE (1)
PHEWE:
„Assessment and prevention of acute health effects
and weather conditions in Europe“
The project is covering almost every climatic region of
the European continent.
Daily cause-specific mortality data was provided from
Athens, Barcelona, Budapest, Dublin, Helsinki,
Ljubljana, London, Milan, Paris, Prague, Rome,
Stockholm, Turin, Valencia and Zurich
together with meteorological data and air pollution
data between 1990 and 2000.
Analitis et al. 2008
Results from a European Project: PHEWE (2)
- Cold Effects Analysis was done city-specific and then pooled using meta-analysis
methodology.
A 1°C decrease in minimum apparent temperature was
associated with a 1.35% [1.16; 1.53] increase in the daily
number of total natural deaths.
Cardiovascular: 1.72% [1.44; 2.01]
Respiratory: 3.30% [2.61; 3.99]
(all for cold season)
Cerebrovascular: 1.25% [0.77; 1.73]
The increase was greater for older age groups and also in on average
warmer (more southern) cities. It persisted up to 23 days with no
evidence for mortality displacement.
Results from PHEWE (3):
City-specific and pooled %-increase in mortality per 1°C decrease in
minimum apparent temperature (average of lag 0-15)
Total natural
Respiratory
Cardiovascular
Cerebrovascular
Results from PHEWE (4):
Combined (all 15 cities) distributed lag curves up to 30 days of the
mortality effect per 1°C decrease in minimum apparent temperature
Results from PHEWE (5)
- Heat Effects and Mortality Analysis was done city-specific based on generalized estimating
equations and then pooled using Bayesian random effects metaanalysis.
The city-specific exposure-response functions had a V- or J-shape, with
a change-point that varied mong cities. For Mediterranean cities this
threshold was 29.4°C and for north-continental cities it was 23.3°C.
A 1°C increase in maximum apparent temperature (in the warm
season) was associated with a 3.12% [0.60; 5.72] increase in
the daily number of total natural deaths in Mediterranean cities
and with a 1.84% [0.06; 5.72] increase in north-continental
cities.
Stronger estimates were found for respiratory mortality and for the
older age group.
The effect was limited to the first week following temperature excess,
with evidence for mortality displacement.
Baccini et al. 2008
- Heat Effects and Hospital Admissions In 12 cities also daily hospital admissions for cardiovascular,
cerebrovascular and respiratory causes were analyzed by age.
For the 75+ age group there was an increase in
respiratory admissions by 4.5% [1.9; 7.3] for
Mediterranean cities and 3.1% [0.8; 5.5] for northcontinental cities for a 1°C increase in maximum apparent
temperature above a threshold (in the warm season).
The mechanisms are poorly understood and it is unclear why
high temperature increases cardiovascular mortality but not
cardiovascular hospital admissions.
Michelozzi et al. 2009
- Mortality Exposureresponse
functions:
Baccini et al. 2008
- Hospital Admissions -
Age 75+
City-specific and pooled estimates (regression coefficients and 95% confidence intervals)
of the effect of maximum apparent temperature on daily hospital admissions.
Age 75+
Age 75+
The Project EuroHEAT
The main objectives of the project were:
To develop an operational definition of “heatwave”;
To evaluate the health impacts of heatwave episodes in
population subgroups;
To compare the impact of summer 2003 heatwaves with the
effect of heat-waves observed in the other years of the study
period;
To evaluate the specific contribution of heatwave characteristics
in terms of duration, intensity and timing (population
susceptibility) within summer period.
Climate change models for Europe show that over the next century
heatwaves will become more frequent, more intense and
longer lasting, especially in the Mediterranean regions, but also in
Northern areas currently not very susceptible to heat wave events.
(Meehl and Tebaldi 2004)
D‘Ippoliti et al. 2010
EuroHEAT – Results (1)
Results indicate that
Intensity (apparent temperature higher than monthly 95th
percentile)
Duration (duration longer than median value)
Timing (first heatwave in summer, heatwaves in distance of 1-3
days after the last one, heatwaves more than 3 days from the last
one)
influence the risk on mortality.
Females and older age groups were more susceptible to heatwave
effects.
During the years under study (excluding 2003) the strongest impact on
mortality was observed in Mediterranean cities.
However, 2003 the highest impact was observed where heatwave
episodes are rare events (conditions not typical for the local climate).
Heatwaves by duration and intensity
Heat waves were defined as:
1) periods of at least two days with Tappmax
exceeding the 90th percentile of the monthly
distribution
or
2) periods of at least two days in which Tmin exceeds
the 90th percentile and Tappmax exceeds the
median monthly value.
Heatwaves summer 2003 vs. other years
Interactive Effects of Heat and Pollutants
(Ozone and PM10)
low ozone
high ozone
* significant pooled interaction coefficient
*
*
low PM10
high PM10
* significant pooled interaction coefficient
Low pollutant day: <25th percentile;
High pollutant day: >75th percentile
85+
75-84
0-64
95% CI
65-74
Respiratory mort.
85+
CVD mort.
65-74
Total mort.
65-74
85+
75-84
65-74
0-64
95% CI
*
0
Respiratory mort.
85+
75-84
65-74
0-64
CVD mort.
85+
75-84
65-74
Total mort.
*
20
0-64
0
40
0-64
20
60
85+
*
*
80
75-84
40
100
75-84
% increase in daily mortality
60
0-64
80
Adjustment for Pollutants
Summary
Evidence for synergistic effects between PM10 and
ozone and heat-wave episodes on total mortality:
Heatwave effect on total mortality 54% higher on high
compared to low ozone days in the 75-84 age-group;
30
Increase of heatwave effect 36% and 106% in the 7584 and over 85 years age-groups, respectively, on
high PM10 days;
20
10
Similar pattern for effects on cardiovascular mortality;
85+ yrs
None
O3
NO2
SO2
CO
PM10
75-84 yrs
None
O3
NO2
SO2
CO
PM10
65-74 yrs
None
O3
NO2
SO2
CO
PM10
0-64 yrs
0
None
O3
NO2
SO2
CO
PM10
40
No statistically significant synergy evident for
respiratory mortality;
Heatwave effect estimate smaller when adjustment for
PM10 or ozone was considered:
Lack of adjustment for ozone and especially PM10
when assessing the effect of heatwaves on mortality
results in overestimated effect parameters!
Project MOHIT (1):
Mortality, Myocardial Infarction and
Temperature in Bavaria
Objective:
Analysis of daily counts of total natural deaths in the Bavarian cities Munich,
Nuremberg and Augsburg for the years 1990 to 2006
Pooled exposure-response functions for 2-day and 15-day average air temperature
and non-accidental mortality:
-10
0
Lag 0-14
0.8 1.0 1.2 1.4 1.6 1.8 2.0
0.8 1.0 1.2 1.4 1.6 1.8 2.0
Relative
Risk
Lag 0-1
10
20
-10
0
10
Breitner et al. 2014
20
Temperature
Project MOHIT (2):
Relative
Risk
-10
Lag 0-1
0
Lag 0-14
0.8 1.0 1.2 1.4 1.6 1.8 2.0
0.8 1.0 1.2 1.4 1.6 1.8 2.0
Pooled exposure-response functions for 2-day and 15-day
average air temperature and cardiovascular mortality:
10
20
-10
0
10
20
Temperature
Project MOHIT (3):
3.0
Relative
Risk
Lag 0-1
Lag 0-14
1.0
1.0
1.5
1.5
2.0
2.0
2.5
2.5
3.0
Pooled exposure-response functions for 2-day and 15-day
average air temperature and respiratory mortality:
-10
0
10
20
-10
0
10
20 Temperature
Project in Beijing, China
Daily counts of cardiovascular deaths of adult residents (older
than 14 years) in the urban area of Beijing (7,072,000
residents) for the period Jan. 2003 to Aug. 2005
Cold period:
Warm period:
Exposure-response
functions:
Liu et al. 2011
Weather Extremes, Mortality and Susceptibility (1)
Effect modification by medical condition of the effect of extreme hot and extreme cold
temperature (1st and 99th percentiles of temperature) on total mortality;
Meta-analysis (123 and 111 US cities, respectively) during 1985–2006, among Medicare enrollees.
Estimates: relative odds of dying on an extreme temperature day for persons who had the
medical condition compared with persons who did not have the condition.
8% [4%, 12%] 7% [1%, 13%]
7% [3%, 11%]
6% [4%, 8%]
Zanobetti et al. 2013
Weather Extremes, Mortality and Susceptibility (2)
Effect modification by subject and area-level characteristics of the effect of extreme
hot and extreme cold temperature on total mortality.
Temperature between Neighbouring Days and Risk
of Mortality
Brisbane, Australia: 1996-2004
and
Los Angeles, U.S.: 1987-2000
TC: temperature change; NEM: non-external mortality, CVM: cardiovascular mortality,
RM: respiratory mortality
Guo et al. 2011
Ambient Temperature and Mortality among the Elderly–
A Systematic Review and Meta-analysis on 15 studies
Combined estimates of temperature
variation on all-cause mortality among
the elderly for an exposure lag of 0 days.
Elderly: Age > 65 years
High temperatures:
2-5% increase in all-cause mortality for 1°C increase.
No lagged effects.
Low temperatures:
1-2% increase in all-cause mortality for 1°C decrease.
Lags up to 9 days.
Yu et al. 2012
High Temperature and Cardiorespiratory Morbidity –
A Systematic Review and Meta-analysis on 21 studies (1)
+2.0% [-1.4; 5.5]
+3.2% [-3.2; 10.1]
Meta-analysis of heat effects (1°C increase in temperature) on respiratory morbidity.
Estimates are for baseline of 0 lag days.
Each central square is proportional to the study’s weight in the meta-analysis.
Turner et al. 2012
Meta-analysis of heat effects
(1°C increase in temperature)
on cardiovascular morbidity.
Estimates are for baseline of
0 lag days.
Each central square is
proportional to the study’s
weight in the meta-analysis.
-0.1% [-1.8; 1.6]
-0.5% [-3.0; 2.1]
Turner et al. 2012
-1.0% [-11.3; 10.5]
+1.0% [-7.0; 9.7]
+0.3% [-11.8; 14.1]
Meta-analysis of heat effects (1°C increase in temperature) on morbidity related to stroke,
acute coronary syndrome/MI, and asthma. Estimates are for baseline of 0 lag days.
Each central square is proportional to the study’s weight in the meta-analysis.
Turner et al. 2012
Heat-related Emergency Hospitalization for
Respiratory Disease
4.3% (3.8; 4.8)
Objective:
To estimate the risk of hospitalization
for respiratory diseases associated
with outdoor heat in the U.S. elderly
(> 65 years).
Database:
Approximately 12.5 Mio. Medicare
beneficiaries in 2013 urban U.S.
counties, 1999 – 2008.
Additional Result:
Counties´relative risks were
significantly higher in counties with
cooler average summer
temperatures.
(10 °F = 5.6 °C)
Anderson et al. 2013
Study on Temperature Effects on the
Occurrence of Myocardial Infarction (MI)
Study period:
01.01.1995 – 31.12.2004
Relative risk estimates for daily numbers of
MI events per 10°C increase in temperature
Study area:
City of Augsburg and two
adjacent areas (Germany)
Data:
Daily counts of MI events
(MI registry Augsburg:
age restriction 25-74 years)
Categories:
- All MIs (n=9801, age 63 ± 9)
- Survived > 28 days (n=4838)
- Coronary deaths (n=4963)
- First MI (n=6902)
- Recurrent MI (n=2030)
→ adjusted for time trend, season, weekday effect
and relative humidity (same lag as temperature)
Wolf et al. 2009
Temperature Effects on MI occurrence:
Relative Risk for MI Events per 10°C Increase
in Temperature
average winter temperatur
average summer temperatur
Cold, medium and warm summers: Cold, medium and warm winters:
Wolf et al. 2009
Temperature, MI, and Mortality
Results from the Worcester Heart Attack Study
Objective:
To examine the association of apparent temperature with acute MI occurrence and
with all-cause in-hospital and postdischarge mortality + effect-modification by
sociodemographic characteristics.
Results:
In summary: Exposure to cold increased the risk of acute MI, and exposure to
heat increased the risk of dying after an acute MI.
An IQR-decrease in apparent temperature was associated with an increased risk
of acute MI on the same day:
hazard ratio = 1.15 [1.01–1.31].
Extreme cold during the 2 days prior was associated with an increased risk of
acute MI:
hazard ratio = 1.36 [1.07–1.74].
Extreme heat during the 2 days prior was associated with an increased risk of
mortality:
hazard ratio = 1.44 [1.06–1.96].
Persons living in areas with greater poverty were more susceptible to heat.
Madrigano et al. 2013
Ambient Temperature and Activation of
Implantable Cardioverter Defibrillators
Objective:
To study timing and activation of ICDs (serious cardiac arrhythmias) in association
to daily outdoor temperature.
London, 1995-2003
Results:
Decrease of 1°C: risk of ventricular arrhythmias
up to 7 days later increased by 1.2% [-0.6; 2.9];
Decrease of 1°C below 2°C: risk of ventricular
arrhythmias increased by 11.2% [0.5; 23.1];
Patients over age of 65 exhibited highest risk.
McGuinn et al. 2012
Possible Pathways /
Mechanisms:
Results from selected projects
Study in Clinic of Cardiac Rehabilitation
(Curschmann-Klinik, Timmendorfer Strand)
•
Longitudinal study with repeated measurements (retrospective analysis) on 872
patients (90% men) from January 1994 to January 1995
•
Patients suffered from congenital or aquired heart diseases (59% had a
myocardial infarction)
•
4-6 weeks rehabilitation stay at Curschmann-Clinic, Timmendorfer Strand
•
Age: 21-84 years (58±9 years) and BMI: 17-45 kg/m² (26±3 kg/m²)
•
No changes in medication
•
2-5 bicycle-ergometries per patient (25 Watt-steps with 2 minutes each and a
recovery phase afterwards for 5 minutes).
Only patients with >75 Watt were included.
•
2349 observations available for analysis
•
Outcome 1: Heart rate and blood pressure (before ergometry at rest, at each
step and in recovery phase)
•
Outcome 2: ECG-anomalies: ST-depression (during exercise), ventricular
extrasystoles (during and after exercise), angina pectoris symptoms (during
exercise)
Schneider et al. 2008
Results Men: ST-depression (during exercise)
in Association with Decreasing
Temperature and Humidity
Odds Ratio for ST-segment depression
per interquartile range decrease
in the meteorological parameters
4
lag0
lag1
lag2
lag3
4-day-ave.
3
2
1
0
Air temperature
Water vapor
pressure
Equivalent temperature
Meteorological parameters (different lags)
Percent change of mean of heart frequency
at rest per interquartile range increase
in the meteorological parameters
Results Women: Heart Rate (before
exercise) in Association with
Increasing Temperature
15
10
5
0
-5
lag0
lag1
lag2
lag3
4-day-ave.
-10
-15
Air temperature
Odds Ratio for ventricular extrasystoles
(during ergometry) per interquartile range
increase in the meteorological parameters
Results Women: Ventricular Extrasystoles
(during exercise) in Association with
Increasing Temperature and Humidity
8
lag0
lag1
lag2
lag3
4-day-ave.
6
4
2
0
Air temperature
Water vapor
pressure
Schneider et al. 2008:
European Multicenter-study AIRGENE
in Myocardial Infarction Survivors
AIRGENE study centers and mean air
temperature (±SD) during study
period:
• Helsinki, Finland: 3.1 °C (±6.9)
• Stockholm, Sweden: 4.7 °C (±6.2)
• Augsburg, Germany: 10.2 °C (±9.6)
• Rome, Italy: 13.5 °C (±6.1)
• Barcelona, Spain: 15.2 °C (±4.6)
• Athens, Greece: 17.4 °C (±7.0)
Peters et al. 2008
The AIRGENE Study
AIRGENE:
“Air pollution and inflammatory response in myocardial
infarction survivors: gene-environment interactions in a high
risk group”
Objective:
Analysis of the association between air pollutants (and air
temperature) and three inflammatory blood markers:
C-reactive protein (CRP), interleukin-6 (IL-6) and fibrinogen in
1,003 myocardial infarction survivors.
Analysis of gene-environment interactions with selected
candidate genes.
Study design:
Multicenter epidemiological study with 6-8 repeated
measurements per participant within 13 months (19.05.03 –
30.07.04)
Usable blood samples: 5,813
Results: C-reactive Protein
Air temperature effect estimates on CRP
20
Increase in CRP
with decreasing air
temperature with
a delay of 1-4 days.
%-change of GM** in CRP-level
C-reactive protein
10
0
-10
-20
-30
Hel
(Plotted for an increase
of 10°C in air temperature)
Sto
Aug
Rom
Bar Ath
pooled
Hel
Sto
Aug Rom Bar Ath
-40
Lag 1
5-day-ave.
pooled
Results: Interleukin-6
Air temperature effect estimates on IL-6
15
Interleukin-6
with decreasing air
temperature with
a delay of 1-4 days.
10
%-change of GM** in IL-6-level
Increase in IL-6
5
0
-5
-10
-15
Hel
Sto
Aug
Rom
Bar Ath
pooled
Hel
Sto
Aug Rom Bar Ath
-20
Lag 1
5-day-ave.
pooled
Results: Fibrinogen
Air temperature effect estimates on Fibrinogen
10
Increase in fibrino-
air temperature
mainly with a delay
of 3 days.
%-change of AM** in fibrinogen-level
gen with decreasing
Fibrinogen
5
0
-5
-10
-15
Hel
Sto
Aug
Rom
Bar Ath*
pooled
Hel
Sto
Aug Rom Bar Ath*
-20
Lag 1
5-day-ave.
*Athens: no data on fibrinogen
**GM: geometric mean, AM: arithmetic mean
pooled
Possible Mechanisms for Cold Effects (1)
Stimulation of cold receptors in the skin
→ Activation of sympathetic nervous system with a rise in catecholamine
level.
Vasoconstriction
→ Increase in heart rate, blood pressure, central blood volume, increase in
volume per beat
→ Increase in workload for heart muscle, which means an additional need
for oxygen
→ Can lead to ischemia in already diseased persons
→ Myocardial infarction or angina pectoris
Significant increase of fibrinogen during cold periods (Marchant et al. 1994)
Seasonal variations of inflammatory markers with higher levels in winter
(Sung et al. 2006; Crawford et al. 2003)
Respiratory infections in winter: additional rise in fibrinogen level
(Woodhouse et al. 1994)
Possible Mechanisms for Cold Effects (2)
Temperature influence on blood lipids und hemostasis (Elwood et al. 1993)
Less physical activity in winter
Changed nutrition habits in winter
→ Risk for myocardial infarction higher
(Yarnell et al., 1991 and Ridker et al., 1991)
Stronger temperature influences in the elderly:
• Thermoregulation efficiency is reduced, therefore less control against
cold stimuli
• With increasing age the fibrinolytic system changes
→ Increased risk for myocardial infarction
Possible Mechanisms for Heat Effects
„Overload“ for thermoregulation:
Vasodilatation, drop in blood pressure, less evaporization of
perspiration from skin into environment possible
→ This leads to problems in the cardiovascular system and
might lead to ischemia.
Heat stress:
Dehydration, loss in electrolytes, significant increase in blood viscosity,
changes in hemostasis (release of platelets into circulation, increase of red
and white blood cell counts, increase in plasma cholesterol due to water
loss and reduced plasma volume)
→ This might lead to a coronary thrombosis but also to cerebrovascular
problems.
Elevation of minimum temperatures (night time) does not allow recovery
from severe heat stress experienced during the day.
High levels of ozone (O3) might have a contributory effect.
Climate Change and its Potential
Impacts on Health
Overview
The world‘s climate has always changed as a result of natural cycles and
catastrophic events but there is now strengthening evidence that for the
first time it is changing as a result of human activity.
The rate of change is predicted to be rapid and global climate models suggest
that average temperatures are likely to increase by 1.4 to 5.8°C by the
end of the 21st century (IPCC 2007).
Extremes of weather are predicted to become more common, and sea
levels to rise.
These changes may affect the health of human populations.
Climate change is considered to be one of the key environmental threats of
the coming century, but how to respond to it remains widely debated.
The PESETA Project estimated 86.000 extra deaths per year with a global
mean temperature increase of 3°C in 2071 to 2100 in Europe.
But: Cold weather / cold spells will still affect Europe (particularly poorer
households). Most European countries suffer from 5-30% excess winter
mortality. This could be relevant as climate change also includes more
temperature variability and temperature extremes.
Impacts of Weather and Climate on Health
Types of impact:
Direct effects from thermal
extremes, severe weather
events, food and water-borne
illness and changes in the
distribution of vector-borne
disease.
Indirect effects from
disruption of food
production and water
resources, social dislocation
and reduced productivity.
Critical Issue = Mitigation
- How to adapt?
- How to limit impact on human
health?
- Provide arguments for reducing
emissions!
WHO 2008
Concerns
Rapidity of change:
Although profound climate changes have occurred over time, a rise of several °C
over the next 100 years would represent a very rapid change to which ecosystems
would have little time to adapt. The temperature increase since the last Ice Age
took thousands of years, and plants and animals could gradually migrate across
latitudes.
Regional variation:
Although we refer to climate change as a single phenomenon, there are predicted
to be significant variations in the change of temperature and precipitation, which
may therefore produce more profound impacts for some populations (e.g. lowincome countries who also have least capacity to adapt).
Vulnerability of fixed human settlements:
A climate change now would be the first major change since agriculture began.
Modern societies are complex and sophisticated, but this may also make them
more vulnerable. For example the location of cities is fixed and infrastructure can
only be slowly changed and we have become more and more dependent on
intensive methods of food production which might be disrupted in some areas.
(Find adequate technologies that „solve“ some of the climate change problems?)
Problems
Difficult to quantify health impacts of climate change as they relate to an
uncertain future and it is difficult to define the climate sensitivity of diseases.
It is difficult to make assumptions about the capability of people to
adapt to a warmer climate (physiological habituation, behavior, structural
changes to the built environment) so that they are not as sensitive as expected
to heatwaves and other weather events associated with the new climatic
conditions.
Epidemiological studies cannot really study the association between
climate and health, but instead only the association between weather
and health:
Time-series analyses in which short-term fluctuation in health is analyzed in relation to
fluctuations in temperature, rainfall etc. measured at a similar temporal resolution.
To study climate and health would mean to study long-term health experience of
populations exposed to different climates which is difficult as populations differ for many
reasons other than climate.
But even though time-series reflect only a short-term association between weather and
health, their results can be taken as reasonable evidence of climate impacts as for
example the effect of a heat period represents a health burden that may be even more
important in the future as the frequency of heat periods is likely to increase during the
new warmer climate.
Change in Mean Global Temperature Over Last
150 Years
1950s: Concerns of the beginning of a new ice age as the last ice age ended 12.000 years ago.
First belief: Nuclear bomb tests polluting the atmosphere were reason for temperature drop.
But: Unusual number of volcanic eruptions – volcanic dust in atmosphere reduced insolation
1998 warmest year on record so far (until 2008)!
Muller 2008
Anthropogenic Influence
Greenhouse gases - increases
Human and natural sources
in last 2000 years:
and sinks:
CO2: Fossil fuel use in transportation, heating, cooling + deforestation, decay of plant matter
CH4: Agriculture, landfills, naturally emitted from wetlands
N2O: Fertilizer use, fossil fuel burning
Halocarbon gas like chlorofluorocarbon: Human activities
O3: Continually produced and destroyed in atmosphere, troposphere: human activities
Water vapor: Only small influence of human activities (via CH4)
Aerosols: Small particles that vary in size, concentration and chemical composition (natural and due to human
activities like fossil fuel burning)
IPCC 2007
Changes in Extreme Events
Since 1950, the number of heat waves has increased as well as increases in warm nights.
The extent of regions affected by droughts has also increased (less precipitation, more
evaporation). But also heavy daily precipitation events that lead to flooding have increased
(not everywhere). Tropical storm and hurricane frequencies vary from year to year, but
evidence suggests increases in intensity and duration (problem: changes in registration
procedures as well).
Type, frequency and intensity of extreme events are expected to change and these
changes can occur even with relatively small climate changes.
However, abrupt climate changes (collapse of West Arctic Ice Sheet, rapid loss of Greenland Ice
Sheet or large-scale changes in ocean circulation are not considered likely to occur.
Cold nights
Warm nights
Cold days
Warm days
IPCC 2007
Rising Sea Level
There is strong evidence that
global sea level rose in the
20th century and is currently
rising at an increased rate
after a period of little change
between 0 and 1900.
The rise is projected to be
even larger (depending on the
scenario used).
Major causes are the
thermal expansion of the
oceans due to the warming
climate as well as the loss
of land-based ice due to
increased melting.
IPCC 2007
Temperature Variability and Long-term
Survival among Elderly People
Combined results across
135 cities in four disease cohorts
(hospitalization) based on U.S.
Medicare data from 1985-2006.
YOUNG: subjects aged ≤74 y;
OLD: subjects aged >74 y
and summer temperature SD
(June – August).
Overall Mortality Hazard Ratios (per 1°C increase in summer Temp. SD):
Chronic heart failure 1.028 [1.013; 1.042]; COPD 1.037 [1.019; 1.055];
Diabetes 1.040 [1.022; 1.059]; Myocardial infarction 1.038 [1.021;1.055].
Higher effects for elderly persons and lower effects in cities with higher
percentages of land with green surface.
Temperature and Years of Life Lost* in Brisbane, Australia
(Baseline: 1996-2003 and Projection: 2046-2053)
Hot: >23°C
Cold: <23°C
*YLL: combines number of deaths
with life expectancy
Huang et al. 2012
Climate Change and Future Temperature-related Mortality
in 15 Canadian Cities: Cold Effects
(Baseline: 1981-2000 and Projections: 2031-2050, 2051-2070,
2071-2090, annual mortality rate per 100,000 population)
Martin et al. 2012
Climate Change and Future Temperature-related Mortality
in 15 Canadian Cities: Heat Effects
(Baseline: 1981-2000 and Projections: 2031-2050, 2051-2070,
2071-2090, annual mortality rate per 100,000 population)
Martin et al. 2012
Projection of Heat-related Mortality under Climate
Change Scenarios: A Systematic Review
Time periods used by studies of
climate change and projected
mortality, ordered by date of
publication. Blue lines show the
baseline time periods; black lines
or black circles show the projection
time periods.
Included: 14 studies
Most projections showed that climate change would result in a substantial increase in
heat-related mortality.
Important factors: historical temperature-mortality relationship, population, acclimatization,
socio-economic development, adaptation strategies, land-use patterns, air pollution,
mortality displacement
Huang et al. 2011
Climate Change and Potential
Population Adaptation (1)
Example 1: Reduced mortality impact of high
summer temperatures over time (1973-1977
vs. 2003-2006) in U.S. („New England“-part)
Example 2: Non-linear exposure-response
relationships for 1993 vs. 2006
USA: attenuation in risk more pronounced
for less extreme temperatures;
Spain: attenuation is actually stronger for
more extreme heat;
However: excess mortality risk associated
with heat persists in all countries.
Schwartz et al. 2015,
Gasparrini et al. 2015
Climate Change and Potential
Population Adaptation (2)
combined
For 209 U.S. cities: projected change
in premature temperature-attributable
deaths per million study city residents
relative to the 1990 baseline by month
for two climate models.
(GFDL-CM3 projects higher
temperature increases as MIROC5)
Schwartz et al. 2015
For Further Reading
Meyers Lexikonverlag: „Wie funktioniert das? Wetter und Klima“
Angela Schuh: „Biowetter - Wie das Wetter unsere Gesundheit
beeinflusst“ and „Angewandte medizinische Klimatologie“
Paul Wilkinson: „Environmental Epidemiology“
Richard A. Muller: „Physics for Future Presidents – The Science behind
the Headlines“
McMichael A, Campbell-Lendrum D et al.: „Climate Change and Human
Health: Risk and Responses“. WHO 2003.
IPCC-Reports 2007 + 2013/2014. „The Scientific Basis“ and „Frequently
Asked Questions“
Basu R and Samet JM: „Relation between elevated ambient temperature
and mortality: a review of the epidemiologic evidence.“ Epidemiologic
Reviews (2002); 24(2): 190-202.
Interesting Websites
The Hadley Center for Climate Prediction and Research:
www.metoffice.com/research/hadleycentre
The Tyndall Centre for Climate Change Research:
www.tyndall.ac.uk
European Centre for Environment and Health:
www.euro.who.int/ecehrome
Intergovernmental Panel on Climate Change: www.ipcc.ch
WHO: www.who.int
National Oceanic and Atmospheric Administration:
www.noaa.gov
Any
Questions ?
Dust devil / weak tornado
Praia a Mare in Calabria
16 September 2008

Climate - MSc Epidemiology

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