Stressors in the Environment (1) Flashcards
1
Q
What is stress and why does it exist?
A
- Stress: a state of psychological and physical tension produced when there is a mismatch between the perceived demands of the situation (the stressors) and the individuals ability to cope, causing both an emotional and physical response
- needed our physical stress response to equip us with the energy to escape predators
- in modern life, can still be useful as it motivates us to complete tasks (eustress) but extreme stress can still be harmful
2
Q
What is the body’s response to short term stress?
A
- stressor perceived
- sympathetic nervous system aroused
- adrenaline released from the adrenal medulla
- this causes increased heart rate and blood pressure
- instantaneous response
3
Q
What is the impact of short term stress?
A
- Yusuf et al. examined chronic stressors in the INTERHEART study
- involved 52 countries, sought to identify major risk factors for cardiovascular disease
- compared 15,000 people who had heart attacks with those who did not
- found environmental stressors contributed even more than obesity
- shows short term stress can have potentially life changing consequences
4
Q
What is the body’s response to long term stress?
A
- stressor perceived
- hypothalamus aroused, producing a hormone called CRF
- this is detected by the pituitary gland, which releases ACTH into the bloodstream
- this causes the adrenal cortex to release cortisol
- cortisol affects glucose metabolism by mobilising and restoring energy supplies to power the stress response
- however, cortisol also has damaging effects, as it suppresses the immune system
5
Q
What is the impact of long term stress?
A
- cortisol suppresses the immune system, known as immunosuppression
- Cohen et al. gave 420 participants small doses of a cold virus or placebo drug and assessed stress levels from the previous 12 months
- found that those who experienced more stress more likely to contract the cold virus and display symptoms
- shows that long term stress can make us more susceptible to illness
6
Q
What is the general adaptation system?
A
- Selye (1936) found that humans and animals respond to stressors through a three stage physiological response called the General Adaptation System
- Alarm reaction (6-48hrs after stress, includes loss of muscle tone and drop in body temp)
- Resistance (more careful use of the body’s resources)
- Exhaustion (when stress is prolonged, the physiological systems involved in alarm reaction and resistance become ineffective - stress related diseases become more likely)
7
Q
What research suggests stress is caused by noise?
A
- Lundberg and Frankenhauser found increased levels of stress when participants weren’t in control of noise that was played when they concentrated on a mental arithmetic task, compared with those who had control
- measured physiological reactions and took self report measures
8
Q
What research suggests stress is caused by temperature?
A
- Peng et al. examined the relationship between temperature and admissions into mental hospitals in Shanghai for 8yrs
- almost 94,000 admissions made
- significantly more admissions occurred within 24 hours of a very hot day
- also found that colder days had no such effect
9
Q
What is the background to Black and Black?
A
- research shows that aircraft noise can increase stress levels
- as stress makes people less tolerant of unwanted sound, this can quickly become a vicious cycle
- for this reason, governments, air traffic controllers and airport management aim to minimise exposure to aircraft noise as much as possible
10
Q
What was the aim of Black and Black’s study?
A
- to develop an understanding of the impact of airport noise on community health and wellbeing in order to inform future public policy
- wanted to answer two questions:
1) is health related quality of life in a community chronically exposed to aircraft worse than in communities not exposed?
2) is long term aircraft noise exposure associated with hypertension in adults via noise stress as a mediating factor?
11
Q
What method did Black and Black use?
A
- Sydney airport selected as a case study
- Questionnaires posted to addresses in two areas -> aircraft noise area (exposed to around 50 planes a day with volume of 70db each) and the control area (no noise and matched on socio-economic measures)
- every property (except those for sale, apartments, commercial buildings or abandoned properties) was sent the questionnaire w/ cover letter explaining the study
- due to area’s ethnic composition, questionnaire translated into Arabic and Greek
12
Q
What were the seven major characteristics examined by the questionnaire?
A
- health related quality of life
- hypertension condition
- noise stress
- noise sensitivity
- noise annoyance
- Demographic characteristics
- Confounding factors
13
Q
How many responded to the questionnaire and what were some key features of these participants?
A
- age range 15-87
- those in noise area tended to have higher levels of education and better employment status
- those in noise area more likely to be smokers
- percentage of obesity higher in control area
- those in control area more likely to be married
- more respondents in exposure area had insulted their houses (37%) compared to in the control area (3%)
- those in noise area more likely to respond to questionnaire
14
Q
What were the results of Black and Black’s study?
A
- all four scores for the dimensions of health related quality of life were lower in the aircraft noise group, but not a significant difference overall
- no significant differences in hypertension levels between the two areas, however significant associations between chronic aircraft noise exposure and noise stress, and between noise stress and hypertension, so noise may be an indirect cause of hypertension
- participants in aircraft noise area showed higher noise stress than those in the control group and were more annoyed about traffic noise, even though there was no significant difference in noise sensitivity
15
Q
What was the conclusion of Black and Black’s study?
A
- individuals exposed to long term, high levels of aircraft noise are more likely to report stress and hypertension compared to those not exposed to aircraft noise, impacting their health and related quality of life
