Bellwork: 10/19/2011Collect the following data:

• Temperature Salt Water Tanks Only:

• DO - Phosphate

• Turbidity - Salinity

• Nitrate - Calcium

• Nitrite - Water Hardness

• Ammonia

• pHMake sure to clean out any excess food from your filter and gravel/sand. Scrub off the inside of the glass & clean the outside with Windex once you are finished.

If you are not helping with the water chemistry, you must be working on the following: Groups of 2 or

less!1. You are a doctor in a rural area. A mother brings her 3-month old son in

who is having trouble breathing & vomiting throughout the day. Once you have completed a physical examination you discover that the infant has blue discoloration inside his mouth, as well as blueness on his hands & feet. The mother tells you that they get their drinking water from a local well.

a) What is the name of this condition?

b) Describe the pathway from consumption of a contaminant to the expression of illness.

c) What is the likely source of the contamination?

d) What can be done to immediately treat the child?

e) What can be done within the home to prevent further exposure to contaminants?

f) What can be done locally to prevent this exposure from affecting others?

Non-living Contaminant Review1. What are cyanotoxins? How are they produced? How could this be prevented?

Non-living Contaminant Review2. What type of soils are most vulnerable to high levels of TDS? Why?

Non-living Contaminant Review3. When considering thermal pollution, what are its effects on DO & bacterial growth? How can this be avoided?

Non-living Contaminant Review4. List 3 sources of nitrates in bodies of water:

Non-living Contaminant Review5. What are DBPs? Where do they come from? What are their possible effects on human health? Why do we use them?

Bellwork – 10/15/20121. 2.5 % of the planet's water is fresh water. What

& what percent make up this small amount?

2. List the reactions from the carbonate buffering system from most basic to most acidic.

Microbial Contaminants in water

Types of waterborne pathogens

• Viruses

• Bacteria

• Protozoa

• Helminths

Viruses

• Smallest (0.02 – 0.3 µm)

• Simplest – Nucleic acids (DNA or

RNA)– Protein capsid

Bacteria

• Size: 0.5 –2.0 µm• Simple internal

organization• Envelope: cytoplasmic

membrane, cell wall, and capsule

• Appendages: flagella and/or pili

• Spores: environmentally resistant form

Protozoa

• Size: 2 – 200 µm

• Complex internal organization (nucleus, mitochondria, etc)

• Very complex life cycle (inside and outside of their hosts)

• Flagellates, ameba, ciliates, and sporozoans

• (Oo)cysts: environmentally resistant form

Helminths

• Multicellualr animals• Size: up to 30 cm• Highly differentiated

structures• Very complex life cycle

(inside and outside of their hosts)

• Nematodes, Trematodes, and Cestodes

• Eggs: environmentally resistant form

Transmission of enteric pathogens

Bacteria

Escherichia coli

• Elongated and straight rod

• Size: 0.5-1 µm • ~8,000 serotypes• Acute bloody diarrhea

and abdominal cramps with little or no fever

• 3-5% fatality.

Escherichia coli: Epidemiology

• Involved in 11 drinking water outbreaks with 529 cases and 15 recreational water outbreaks with 387 cases in USA (1971-2000)

• Incidence – 730,000 (estimated) cases (USA)– 210 million cases and 300,000 deaths worldwide– All pathogenic E. coli: 1.5 billion (estimated) case and 3 million death

worldwide• Reservoirs: humans and animals (cattle, goats, sheep, deer, ….)• Incubation period: typically 1-3 days• Duration of illness: 2-12 days• Mode of transmission: Direct (person-to-person) and indirect (fomites,

water, and food)

Salmonella spp.

• Elongated and straight rod

• >2,000 serotypes• Diarrhea, fever,

headache, constipation, malaise, chills, and myalgia

• 12% - 30% mortality

Salmonella spp. : Epidemiology

• Involved in 12 drinking water outbreaks with 2,370 cases in USA (1971-1992)

• Incidence – An estimated1.4 million cases with 500 death in USA– An estimated 21 million cases of typhoid fever and 200,000

deaths occur worldwide. • Reservoirs: humans and animals (cattle, chicken, turkey…)• Incubation period: typically 1-3 days• Duration of illness: 2-7 days• Mode of transmission: Direct (person-to-person) and

indirect (fomites, water, and food)

Vibrio cholerae

• Straight or curved rod• Motile with flagella• 0.5-0.8 µm in width and

1.4-2.6 µm in length

• Profuse watery diarrhea, vomiting, circulatory collapse and shock.

• 40 - 60 % of typical cases are fatal if untreated

Vibrio spp. : Epidemiology

• Involved in 2 drinking water outbreaks with 28 cases in the USA (1971-2000)

• Incidence – 0-5 cases per year in the United States. – A major cause of epidemic diarrhea throughout the developing world. – Ongoing global pandemic in Asia, Africa and Latin America for the last

four decades. • Reservoirs: humans, environmental reservoirs - may be associated

with copepods or other zooplankton • Incubation period: a few hours to 5 days; usually 2-3 days • Duration of illness: several days• Mode of transmission: Indirect (water and food)

Protozoan Pathogens

Protozoa

• Size– Usually 10-50 µm

• smallest: 1-10 µm, largest: 150-200 µm (Balantidium coli)

• Many organells– Nucleus (or nuclei)– Cytosome (cell mouth), food vacuoles, contractile

vacuoles (osmoregulation), Golgi apparatus, mitochondria, lysosomes,…

– Locomotive structures: ameoba, flagella, cilia• Cell cycle and reproduction

– Asexual (binary fission) and sexual (various life stages)

Prokaryotic Cell (left) and Eukaryotic Cell (right)

Mode of transportation

Giardia lamblia: Epidemiology

• Involved in 126 drinking water outbreaks with 28,426 cases and 16 recreational water outbreaks with 684 cases in USA (1971-2000)

• 500,000 estimated cases (200 millions?) worldwide• Reservoir: Human and animals (dogs, beaver, muskrat,

elk, deer, voles, mice, horses, sheep, …)

• Duration of illness: 1-3 weeks • Transmission: Fomites, waterborne, foodborne• High risk groups: children (in day-care centers),

immunosuppressed people, and institutioned populations

Cryptosporidium parvum

• Coccidia• Oocyst

– 4 - 6 m– 4 sporozoites– Thick oocyst wall

• Sporozoite– No locomotive structure

• Immunocompetent people: similar to giardiasis

• Immunocompromised people: life-threating

• Fluid loss: 2-6liter/day (17 liters/day)

• Extra-intestinal infection: respiratory cryptosporidiosis (intestitial pneumonia)

Cryptosporidium parvum: Epidemiology

• Involved in 15 drinking water outbreaks with 421,473 cases and 40 recreational water outbreaks with 11,707 cases in USA(1971-2000)

• Incidence – 1 – 3 % prevalence in USA– 5 % (Asia) and 10 % (Africa) prevalence

• Reservoir: Human and animals (calves, lambs, goats,horses, pigs, deer, squirrel, beaver, muskrat,woodchuck,rabbit, dogs, fox, cat, skunk, raccon, bear, …)

• Infectious dose: < 10 cysts• Incubation period: 7 days• Duration of illness: 1-4 weeks• Transmission: Fomites, waterborne, foodborne• High risk groups: children, immunosuppressed people, institutioned

populations

Emerging Protozoan Parasites

• Toxoplasma gondii

• Microsporidia spp.

Toxoplasma gondii (oocysts)

• Apicomplexa (Coccidia)• Oocyst

– Two phases • A: unsporulated • B: sporulated

– 10 – 13 m– two sporocysts– four sporozoites– distinctive cell walls

• two or three layers• scatter UV • highly persistent in the

environment– soil (months)– moist conditions

(years)

Transmission of Toxoplasma gondii

Toxoplasma gondii: Epidemiology

• Worldwide– 22.5 % prevalence (general population) in USA between 1988-1994– Half billion people in the world

• Unusually high prevalence in France (65-85%): raw or undercooked meat

• High prevalence in Central America: large number of stray cats • Symptoms

– Immunocompetent people: mostly asymptomatic, some flu-like symptoms (swollen lymph glands, muscle aches and pains)

– Immunocompromised people: life-threating• central nerve system disease (encephalitis)• blindness, myocarditis, pneumonia

– Congenital infected children• impaired vision and mental retardation

• Reservoir: Definitive hosts are cats; intermediate hosts are sheep, goats, rodents, swine, cattle, chicken, and birds

• Transmission: Indirect (water and food) and transplacental• High risk groups: infants born to infected mothers, immunosuppressed people