Water Pollution W4

Water sanitation + water quality indicators

Hyponatremia

Overdrinking dilutes sodium in bloodstream. Causes brain to swell + push against skull.

Public Health is

the means of protecting + improving community health

Sanitation is

provision of facilities + services for safe human urine + faeces disposal.

Importance of sanitation

• every day 2 million tonnes of human waste are disposed of in water courses

• some ancient civilisations had advanced systems of drinking water supply + waste collection

Greco-Roman world public health

• diphtheria

• malaria

The Middle Ages (500-1500)

• early urban sanitation

• pandemics e.g., Black Death

• community hospitals commissioned

Revolution of human health (1750-1830)

• national policies e.g., Russian National Health Policy 1763

• Coal + Iron industries

• Fever hospitals + dispensaries

Theories of cholera outbreaks in Britain

• contagionist theory - spread via contact with cholera victims

• Miasmic theory - spread by a ‘miasma of filth’ breathed in from infected air

Cure theories in Britain (18th century)

• rubs with ointments made from wine, vinegar, camphor, mustard, pepper, garlic

• patent medicines - Moxon’s Effervescent Universal Mixture

• prayer

Broad street cholera outbreak 1854

• London’s Soho districts

• growing populations

• lack of sanitation

• 616 died

• ¾ residents fled

• Dr John Snow traced outbreak to Broad Street Pump contaminated by old cesspit with leaking bacteria

James Newlands (1813-1871)

Designed + implemented world’s first integrated sewage system 1848.

Bacteriological era (1875- present)

• ‘Germ theory’

• wide use of antiseptics

• major sewage system improvements

• NHS began 1948

  • escalating public health acts in UK since 1936 Public Health Act

UN Millennium Development Goals Report 2015

2015 - estimated 663 million people worldwide still use unimproved drinking water sources.

2.4 billion using unimproved sanitation facilities.

Spread of cholera again due to:

• poor sanitation effects

• transmitted by food or water

• globally reappearing since 1950

• globally affects 3.5 million

• increasing floods + dry periods present ideal conditions

• Haiti Cholera Epidemic 2010

• Yemen Cholera epidemic 2017

types of sewer systems

• conventional sewers

• separate sewers (rural)

• simplified sewers

• solids-free sewers

• pressurised sewers (high density)

• vacuum sewers (high density)

• channels

some require supporting elements like:

• sewer pumping stations

• transfer stations

types of sewer lines

• main lines (primary) - centre of system

• branch lines (secondary) - extend from main

• house laterals (tertiary) - bring wastewater from houses to branch lines

water is crucial …

• is a pre-condition for human existence + sustainability of planet

• critical for socio-economic development

• reducing global burden of disease

• without proper governance, likely to be increased competition for water between sectors + escalation of water crises

• often key in managing famine, epidemics, inequalities

UN focus on water

• climate change

• disaster

• ecosystems

• finance

• gender

• human rights

• scarcity

water stats

• total volume water is 1.4 billion km³

• 97.5% saltwater, 2.5% freshwater

• 30% of world’s freshwater stored as groundwater

UNMDG

• ensure environmental sustainability

• reduce child mortality

• improve maternal health

• eradicate extreme poverty and hunger

• combat HIV/AIDS, malaria + other diseases

• global partnership for development

STGs

• life below water

• zero hunger

• clean water + sanitation

• improved human health

• food security

• biodiversity

DPSIR framework (worldwide water quality assessment)

D rivers

P ressure

S tate

I mpact

R esponse

water quality factors

• sedimentation

• pH

• erosion

• dissolved oxygen

• runoff

photic zone

epipelagic zone

aphotic zone

mesopelagic, bathypelagic, abyssopelagic

halocline

ability of water to hold its own salt

pycnocline

to do witt water density

thermocline

temperature of water

green water

water from precipitation stored in roots + soils

General water quality indicators

subjective impression: colour, turbidity, taste, odour

general: pH, electrical conductivity, temperature

thermal pollution

rise/fall of a natural body of water

common cause is power station effluents

warmer water decreases level of dissolved oxygen + increase metabolic rate of aquatic animals and increase food consumption.