Lecture 10: Environmental Hazards to Specific Populations
Environmental Hazards to Specific Populations:
1. Children’s environmental health
2. Women’s health and environment
3. Workers and noise hazards
4. Elderly (in high risks) and environmental health
1A. Children’s Environmental Health – why are they so sensitive?
Different exposure patterns between children and adults (don’t act or even have everyday routine
• The limited diet of children
• Behavior unique to children
• How and where children spend their time
• The impact of short stature
The limited diet of children
• Eat, drink 3-4 times more food/drinks in proportion to their body size than adults
• Fewer types of food (adults eat more variety). Example: Breast milk (composed of 3% fat)
• Large quantities of specific foods (kids eat some food more than adults based on diff stuff i.e.
10-15% more apple juice or pears)
• Drink more water relative to their body weight (4 times more than teenagers) Teenagers drink
more soft drinks and sodas.
Behavior unique to children
• Mouthing behavior (2-6 olds touch their mouths about 9 times every hour)
– Ingestion of soil (Deliberate or compulsive behavior): kids with disabilities do it even
– Paint: source of lead. Kids coz of the curiosity can ingest that.
– Small objects like magnets (affect intestines to cause fatal illnesses)
– Infectious agents: don’t wash hands etc.
– Disinfection byproducts: drinking chlorinated water cause more harm to kids than
• Participation in certain athletics and/or risky activities
– Construction sites: physical hazard (asbestos) and chemical hazard.
– Risky playing activities: backyards, storage rooms we could store pesticides, household
– Exposure to sun: kids safer than adults as their mommies take care of them (sunscreen)
How and where children spend their time
www.notesolution.com • Spend most of their time indoors
• Crawling and playing on the floor (dust, pollutants, infectious agents, radon)
• Playing on the grass (pesticides, skin infections)
They are more exposed as they are closer to the ground. Sometimes if they play on the grass
which has residuals of pesticides, it can cause some infections. Also kids can get skin infections
like Zoonosis (from animals to human transfer)
The impact of short stature
• The breathing zone of the adults is 4-6 feet above the floor or ground
• For children is much lower
1B. Children’s Environmental Health
Physiological differences between children and adults
• Higher metabolic rate in children (burn calories faster)
• More active than adults (eat more, drink more, breath more air)
• Dermal adsorption
– higher ratio of skin surface area to body weight than adults,
– skin is more permeable
• Gastrointestinal adsorption
– large surface area of intestines (large surface area makes more chemicals to enter the
– prolong gastric emptying time (babies younger than 1 year need about 6 hours from
ingestion to excretion. Usually adults need only about 4 hours.)
– calcium-lead transport mechanism (for strong bones). Physiologically kids absorb
calcium more. Note: children absorb 50% of ingested lead while adults absorb only 10%.
– lower stomach acidity (especially in first year of life, reduce toxicity of some chemicals
not always increase it. Lower acidity in kids, the heavy metals would b more bioavailable
• Respiratory adsorption
– Breath twice as much air
– Blood- brain barrier (mechanism to prevent entrance to the brain from the blood)
depends on age: only adults have it!!
• Greater blood flow to the brain and other organs
• The size of the some organs relative to body mass is greater (Brain is 13% total size/body mass
for the kids and only 2% for adults)
• Biotransformation processes are less developed
• Rapid growth and development
• More time to develop chronic diseases (kids have the whole life to develop diseases)
2. Women’s Health and Environment
Statistics show increased cases in asthma and associated with new stuff invented/discovered
every day. More allergens seen every day and kids more exposed to them. Stuff quite reactive for
them. Tendency increasing in some types of cancers. Mostly associated with environmental
www.notesolution.com • Role in reproduction and in bearing and nursing of children
• Influence the health of their children
• Carry more fat (physiologically women have a higher fat content than men)
• Live longer than man –on average due to the some hormones.
• Breast cancer (gene, hormones, and synthetic chemicals): 5-10% might be affected by breast
cancer. Research also conducts hormones for breast cancer. Also PCB’s responsible.
• Osteoporosis (deficit of Calcium after menopause: fragility of the bones for older women, lead
and cadmium role)
3. Workers and Noise Hazards
• Most common occupational hazard. Not pleasant environment.
• Damage to the sensitive cells lining the inner part of the ear (damage or loss of hearing)
1. Loss of high frequency sounds (4000