More than 1 billion peoplelack access to
safe drinking water
WHY?
Minimata, Japan
Minamata
• Chisso Corporation, in Minamata, Japan– Plastics, drugs, perfumes
• 1920s, dumped waste in Minamata Bay– Cheaper to pay fishermen than properly
dispose of waste
• 1950s: people had numbness, slurred speech, deformed limbs– Animals (cats, birds) died
• 1960s: linked to mercury in fish
Fecal contamination
• Well over 2 million people—mostly children in poor countries—die of diarrhea every year– Almost always a waterborne illness
• Fecal contamination usually detected by testing for E. coli or fecal coliforms
• Usually: NOT pathogenic
Pathogens in water
• Harder to test for than E. coli
• Include organisms that cause:– Cholera– Typhoid fever– Gastroenteritis– Meningitis– hepatitis
Dhaka, Bangladesh
Agriculture
• Pesticides being applied to lettuce in California
• Danger to applicators and many other environmental issues
• Runoff
Groundwater contamination
• About 50% of US population gets drinking water from groundwater– in agricultural areas, that percentage is
HIGHER
• However: more pesticides detected in surface water than in groundwater. WHY?
Pesticides, Denver metro area
cide
Percent detection Maximum concentration (µg/L)
Surface water
Ground water
Surface water
Ground water
Carbaryl 97 0 5.2 < 0.003
Atrazine 86 43 0.2 0.2
Prometon 86 63 0.16 1.4
Diazinon 69 0 0.24 < 0.002
Simazine 64 30 0.048 0.068
DCPA 61 0 0.029 < 0.002
Tebuthiuron 53 17 0.17 0.79
Chlorpyrifos 31 0 0.11 < 0.004
Malathion 25 0 0.089 < 0.005
Color indicates type of pesticide: Herbicide and Insecticide.
VOCs
Atrazine
• Common herbicide
• Evidence as recently as 2010 that it affects development of ``amphibian gonads’’ frog gender becomes confused
• In agricultural communities, evidence of lowered sperm count among men
Point vs. non-point source