human health and environment review

what is the environment?

Environment is everything that affects a living organism

Effects of environment on human health is so great

Air

Water

Soil

Biota

Manmade environment

(Created by society

your environment is your health but….

its not the only factor influencing your health

gene-environment interaction

Genetic makeup and environmental factor are

independent risk factors

• Models of gene-environment interaction

– Genetic makeup increases exposure to an

environmental risk factor

– Genetic makeup increases susceptibility to an

environmental risk factor

types of hazards

chemical hazard

biological hazard

physical hazard

social or behavioral hazards

genetic traits

core concerns of environmental health

Focus on chemical, biological, physical hazards

Interactions with genetic traits and with

social/behavioral stressors

Emphasis on anthropogenic hazards

Much more than just pollution

As branch of public health, the field of

environmental health takes a population

perspective

atmosphere

CO2 increased 30% since the beginning of the

Industrial revolution

hydrosphere

polluted lake

geosphere

1/3 to ½ of the land surface has been transformed by human action

environmental health

Environmental factors are responsible for 25 % of all

preventable diseases

In developing countries diarrhea and respiratory infections

are heading the list

Protecting the environment has been a mainstream of

public health practices since 1878

Rich & Poor

African Americans & Hispanic & Whites

Developed & developing countries

airborne hazards

outdoor air pollution and indoor air pollution

health effects of outdoor air pollution

The effects depend on the dose or concentration

Asthma

• Particulates and/or SO2 can irritate bronchial passages leading to severe

difficulties in breathing

• Prevalence in the US increased 34%

• The incidence among a children in Australia was one in five, a doubling of

the rate in less than 20 years

• Indoor air pollution is also significant cause

Chronic bronchitis

• Occurs when an excessive amount of mucus is produced in bronchi which

results in a lasting cough

• SO2 and smoking is related to Chronic bronchitis

some health effects of outdoor air pollution

Pulmonary emphysema

• Weakening of the wall of alveoli, they become enlarged and

loss their resilience

• Shortness of breath is the primary symptom

• NO2 is related to emphysema

–Lung Cancer

–Heart disease

–Toxic poisoning

–Eye irritation

–Birth defects

seven common outdoor air pollutants

Primary air pollutants

– Particulate matter

– Carbon monoxide

– Nitrogen oxides

– Sulphur oxides

– VOC (Volatile Organic

Compounds)

– Lead

• Secondary air pollutant

– Ground level Ozone

Particulate Matter

Particles found in the air (dust, soot, smoke, and liquid droplets)

• Vehicles, factories, construction sites, tilled fields, stone

crashing, and all kinds of burning

• Some formed in the air

• Serious health effects

• Big and small

Particulates classified by size

• PM10 —respirable

• PM2.5 —“fine” (mostly from combustion)

• Ultrafine particulates

Carbon Monoxide

Odourless, colourless gas

• Incomplete burning of carbon containing

fuels

• Heaters, woodstoves, gas stoves, fireplaces,

water heaters, automobile exhaust, and

tobacco smoke

• Bigger problem for indoor air pollution

1 000 people die each year in US as result of

CO poisoning (indoor air)

• Sometimes confused with flu or food

poisoning

• Fetuses, infants, elderly and people with heart

and respiratory illnesses are at high risk for

adverse health effects

health effects of carbon monoxide

Interferes with the delivery of

oxygen in the blood to the rest of

the body

• Worsen cardiovascular conditions

• Fatigue

• Headache

• Weakness

• Confusion

• Disorientation, loss of coordination

• Nausea, Dizziness, Deat

prevention meaning

Never leave a car engine running in a shed or

garage or in any enclosed space

• Proper selection, installation, and

maintenance of appliances

• Correct use of appliances

• Good ventilation

• Use CO detectors

Nitrogen Oxides (NOx)

Formed in any type of combustion process

• Involved in formation of ground level ozone

• Forms nitrate particles, and acid aerosols

• Contribute to formation of acid rain

• Transported over long distances

Sulphur Oxides (SOx)

Burning of coal and oil, extraction of metals from ore

• SO2 dissolve in water vapour to form acids

• Acids react with other gases and particles and form

sulphates

• Transported over long distances

• Respiratory illnesses, aggravates existing heart and

lung diseases

VOC (Volatile Organic Compounds)

Variety of organic compounds used as solvent

in industry, automobiles

• Hydrocarbons (HC): methane, butane,

propane

• Some produce photochemical smog (will be

explained later)

Lead (Pb)

Metal

• Vehicles and industrial sources

• Leaded gasoline

• Deposit on soil and water

• Children accidentally can eat soil

• Particularly affects young children

Lead is neurotoxicant

– Effects on

• IQ, cognitive & neurological performance more

broadly

• Cardiovascular mortality, increased lung cancer

risk, kidney toxicity, high blood pressure,

reproductive effects, and oral health impacts

– Heavier burden of exposure on poor,

nonwhite populations

Ozone (O3)

• Summertime pollutant, time of the day, seasonal, climate

• Good in stratosphere

• Bad on a ground

• Transported on long distances

• Lung damage (small airways)

• Shortness of breath, chest tightness, coughing and nausea

• Irritate and damaged eyes, nose, sinuses and throat

• Problem for people who exercise outdoors during the

concentration picks

smog

• Summertime pollutant, time of the day, seasonal, climate

• Good in stratosphere

• Bad on a ground

• Transported on long distances

• Lung damage (small airways)

• Shortness of breath, chest tightness, coughing and nausea

• Irritate and damaged eyes, nose, sinuses and throat

• Problem for people who exercise outdoors during the

concentration picks

airborne hazards

outdoor air pollution

indoor air pollution

indoor air pollution

Contains 2-5 times higher concentration of hazardous

pollutants than outdoor air

• Buildings more airtight to conserve energy, inadequate

ventilation

• People spend about 90% of their time indoors

• Children, pregnant women, elderly, and people with

chronic illnesses are more sensitive

sources of pollutants

Building materials and furnishing

• Asbestos insulation

• Wet or damp carpet

• Furniture made of certain pressed wood products

• Cleaning products and air fresheners

• Personal care and hobbies

Pesticides

• Cooking

• Bathing

• Heating (combustion of

oil, coal, wood)

• Radon

• Smoking

• Outdoor pollution

unhealthy construction materials and sick buildings

Sick building syndrome”

– Nonspecific symptoms experienced by occupants

of a building

• “Sick building” designation

– A building whose occupants experience such

symptoms

• Building-related illness

– Specific diagnosable illness, linked to specific

feature of building

health effects of indoor air pollution

Hard to detect by our

senses

• Symptoms are similar,

need years to develop

• Headaches, tiredness,

dizziness, nausea, itchy

nose, scratchy throat

• Asthma

• Cancer

six common indoor air pollutants

Asbestos

• Formaldehyde

• Mold and Moisture

• Secondhand Smoke

• Radon Gas

• Air Dust

asbestos

Group of six different

fibrous minerals

• Have separable, long,

strong and flexible

heating resistant fibers

asbestos in the environment

Do not evaporate into air or dissolve in water,

do not break down

• Fibers and particles may remain suspended in

the air and carried long distances

• Not able to move through soil

asbestos used in

Building materials (roofing

shingles, ceilings and floor tiles,

paper products, and asbestos

cement products)

– Friction products (automobile

brakes and transmission parts)

– Heat resistant fabrics,

packaging and coatings

how could people be exposed to asbestos?

In industrialized countries, nearly everyone has

asbestos fibers in their lungs

– Some risk of cancer

• People working in some industries

• People living near these industries

• During demolition work and remodeling

• From drinking water

(natural sources or asbestos

containing cement pipes)

health effects of asbestos

Affect the lungs and the membrane

that surrounds the lungs

• Asbestosis- Scar-like tissue, not in

general public

– difficulty breathing,

– often cough,

– heart enlargement

– lead to disability and death

health effects of asbestos

Plaques in the pleural membranes

● Thickened areas of tissue on the lung lining

● Lung cancer, mesothelioma

● Increase risk of getting other types of cancer

(stomach, esophagus, pancreas, kidney)

● Risk increases with smoking

● Not related with birth defects

● Low levels can be measured in urine,

faces, and mucus

formaldehyde is?

Volatile organic compound (VOC), naturally occurring gas, colourless, and strong

smell

• Becomes a gas at normalnroom temperature

• Also released by burning wood and natural gas, by automobile and by cigarettes

Glue or adhesives in pressedwood products (particleboards,MDF, plywood)

• Preservatives in some paints and cosmetics

• Coatings that provide permanent press quality to fabrics and draperies

• Finish used to coat paper products

• Certain insulation materials

health effects of formaldehyde

Allergic reactions

– Watery eyes, burning sensation in the eyes, nose and throat

– Skin rashes

• Nausea

• Coughing

• Chest tightness

• Asthmatic reactions

• Cancer

• Some people very sensitive

mold and moisture

Need moisture, does not need standing water, just requires high relative air humidity

– Bathrooms and

kitchens

– Gym areas

– Locker rooms

– Leaky roof areas

– Damp basements

– On or within wood,

paper, carpet and

foods

mold health effects

Major source of indoor allergens

• Trigger asthma

• Produce Toxins

• Produce Irritants

The way to control indoor mold growth is to

control moisture (maintaining the relative

humidity between 30-60%)

• Often undiscovered

• Produce tiny spores

• Discoloration and odour problems

second hand smoke

Contain 4 000 compounds (CO and

Formaldehyde), 40 are carcinogens

● A non-smoker exposed to secondhand smoke

has a 25% increased chance of developing lung

cancer compared with not exposed non-smoker

● EPA estimates that each year 3 000 lung cancer

deaths among nonsmoking adults in US

● Health Canada estimates that more than 300

non-smokers die from lung cancer each year

because of such exposure

environmental tobacco smoke

Adults: heart disease, heart attack, lung cancer, hearing loss, eyes,

nose and throat irritation

– Children: SIDS, asthma, pneumonia, bronchitis, ear infection and

hearing loss

• Prevalence is generally falling in most countries worldwide,

including many low- and middle-income countries (where

80% of the world's smokers live)

• Rates are stable or decreasing, while the absolute number of

smokers is not declining, and some countries still report rising

numbers.

– More than 8 million people projected to die from smoking-

related causes by 2030

radon gas

Colorless, odorless, tasteless

● Naturally occurring

● Radioactive decay of uranium

● From soil and rock into

basements and lower floors

indoor air

● Dissolved in groundwater,

pumped into wells and then

into homes

● In construction building

blocks

radon gas in buildings

Natural hazards in some regions

– Begins series of rapid breakdowns

– Radon and some progeny are alpha emitters;

lung cancer risk

– Often simple to detect and

remediate

air dust

Heating and cooling -forced air system

• Dust particles

• Pollen or other debris

• Duct Cleaning Service Providers

liquid natural capital

The Earth is a water planet

• Water covers 71% of the Earth’s surface

• Mostly salty water

• No species can live without water

• Sculpting the Earth’s surface

• Moderating climate

• Removing and diluting wastes and pollutants

world problems with water

quanity of water, and quality of water

world probelms

Some areas have lots of water, but the largest rivers are

far from agricultural and population centers

• Lots of precipitation arrives during a short period but

cannot be collected and stored

• Use about 34-54 % of the world's reliable runoff of

surface water and could be using 70-90% by 2030

• Withdrawal- total amount of water removed from a

river, lake or aquifer for any purpose.

– Some may be returned to the source for reuse but not all

– Some lakes and rivers shrin

hydrological proverty

One out of four people do not have regular access to clean

water

• Around 444,000 children under five died from diarrheal

diseases in 2021, a major reduction from previous years

drinking water

Annual reports on local drinking

water quality

• Naturally pure water & distilled

water

• Natural content of minerals in

water

• Surface water - In urban areas

– rivers

– lakes

• Ground water- In rural areas

– wells

– springs

quality of water

Water pH

• Hardness

• Colour

• Turbidity

• Taste

• Odor

• Microbes and Chemicals

contaminants in drinking water

. Microbes

2. Radionuclides

3. Inorganic Contaminants

– Arsenic

– Fluoride

– Lead

– Nitrates (fertilizers –nonpoint sources)

4. Industrial Organic Contaminants

– Pesticides and Herbicides (nonpoint sources)

– Volatile Organic Compounds (VOC)

5. Disinfection byproducts

microbes

Fecal Coliform and E. coli bacteria – contamination

with human and animal wastes, diarrhea, cramps,

nausea, headaches, renal failure, coagulation disorders

• Salmonella typhi – typhoid fever (high fever,

abdominal pain, constipation)

• Shigella sp.- more severe abdominal cramping with

blood and mucus in the stool

• Vibrio cholerae – life threatening, rice-water stools

radionuclides

Alpha emitters

• Beta/photon emitters

• Combined Radium 226/228

• Radon gas

• Radium

• Damage to DNA, Increase risk of getting cancer

radon

a colorless and odorless gas

• Produced by the radioactive decay of uranium, in

particular Uranium-238 with a half life of 4.5 billion

years, and other radioactive minerals

• Radon decays radioactive isotopes Polonium-218

and Polonium-214 which also produces alpha

particles that if breathed or swallowed can cause

several types of cancer

• Uranium is found in several types of minerals

associated with granites, metamorphic gneiss, and

sedimentary rock derived from weathering and

erosion of granite

• Radon can build up in the basement of a home

constructed on soils with high radon levels or if the

basement walls are built of granite

radium

Radium Hot Springs, located within the boundaries of Kootenay National Park, BC

as it appeared shortly after opening (early 1900’s

inorganic contaminants: arsenic

High concentration of arsenic are

poisonous, and lower concentrations

can cause skin cancer and melanosis

(dark pigmentation of the skin)

• After many years of drinking lower

levels, possibility of skin damage,

problems with circulatory system

• Arsenic occurs in more than 200

different minerals that relatively rare

and usually in low concentrations

• Arsenic dissolves very readily in

groundwater and can move long

distances from its source

• When many sources combine, arsenic

can concentrate in toxic level in the

groundwater

inorganic contaminants’: flouride

Fluoride concentration greater than 1.5 milligrams per

liter can become potentially harmful

• Small amounts added to drinking water to promote

dental health

• Exposure to high concentrations of fluoride can cause

dental fluorosis and skeletal fluorosis (bone disease)

• Fluoride is found in the common mineral fluorite and in

certain types of micas and clay minerals

• Highest concentrations of fluoride are found in regions

of volcanic activity

• Unlike arsenic ions, the highly reactive fluoride ions in

the groundwater tend to form chemical compounds

within short distances of its source, therefore, high

levels of fluoride are typically found close to its source

material

inorganic contaminats : lead

Lead pipes are banned

• Anemia

• Brain, kidneys and nervous

system damage

• Appetite loss

• Abdominal pain

• Constipation

• Fatigue

• Sleeplessness

• Irritability

• Headache

• Miscarriages and stillbirths

• Most serious for young children (intellectual development,

behavior, size and hearing of infants)

inorganic contaminants: Nitrates

Inhibits the red blood cell’s ability

to transfer oxygen

• Methemoglobinemia – oxygen

starvation, cyanosis (bluish

discoloration of the skin and lips)

• Spontaneous abortion and neural

tube defects

industrial contaminants: pesticides and herbicides

Chlorinated Hydrocarbons

- DDT, Chlordane, Lindane

- Persistent, bioaccumulating,

biomagnifying

- Not mammal-toxic

- Very negative ecological

effects

Organophosphates and Carbamates

-Round-up (glyphosate)

(grasses)

-Metolachlor, Alachlor

(weeds)

-Triazines 2,4-D; 2,4,5-T

(many plants)

- Rapid decay, not persistent

- Not bioaccumulating and not biomagnifying

but

-Very mammal-toxic

industrial contaminants: MTBE (methil0tert-butly ether)

Fuel additive, replace the use of lead as

octane enhancer

• Used to reduce carbon monoxide and ozone

levels caused by auto emission

• Leaking of underground tanks, to some extent

from air deposition

drinking water from household wells

Vulnerable to contamination by

upgradient land uses (e.g., agriculture,

septic systems)

• Make sure that well is built properly

• Check the water regularly

• Naturally occurring contaminants,

depending on geology (radionuclides,

nitrate and nitrite, heavy metals,

fluoride) Man-made contaminants

– Improper use of fertilizers,

pesticides, animal manure

– Poorly located septic system

– Leaking underground tanks

– Improper disposal of wastes

– Chemical spills at local industrial

sites

drinking water from household wells: noticeable problems

Visible

– Scum from calcium salts

– Turbid water from dirt, clay or rust

– Green stains on sink caused by high acidity

• Tastes

– Salty taste from high sodium content

– Soapy taste from alkaline minerals

– Metallic taste from acidity or high iron content

– Chemical taste from industrial chemicals

Smell

– A rotten eggs odour from hydrogen sulphide gas

or bacteria

– Detergent odour

– Gasoline smell

– Methane gas smell from organic matter in water

– Chlorine smell from excessive chlorination

how is drinking water treated?

Groundwater

– Naturally filtered

– Less organic matter

– Often does not need any treatment

• Water from rivers, lakes and reservoirs

– Basic treatment steps for drinking water

• Initial settling (creates sludge)

• Coagulation and flocculation of tiny suspended particles

• Sedimentation (more sludge)

• Filtering; often sand filter

• Disinfection

disinfection of drinking water

Treatment specifically to kill pathogens

• Chlorination most common

– Effective against bacteria; less so against protozoa

(Giardia, Cryptosporidium) and viruses

– Residual disinfection in distribution system

• Alternatives: granulated activated charcoal, ion

exchange resins, reverse osmosis

• In developing world: boiling water and solar energy

disinfection byproducts

Formed when disinfectants react with naturally occurring

organic and inorganic matter in water

– Trihalomethanes – excess over many years cause liver,

kidney, or central nervous system problems, increased risk

of getting cancer

– Haloacetic Acid – increased risk of getting cancer

– Bromate – increased risk of getting cancer

– Chlorite – children could experience nervous system

effects, some people may experience anemia

household-level water suppy or treatment

Devices for home water treatment

– Point-of-use systems installed at tap (e.g., carbon

filter at kitchen sink)

bottled water

Bottled water

• Expensive; often groundwater source; not likely to

be fluoridated

• Regulated not as drinking water, but as packaged

food

• Often disinfected using ozone or UV light

(no residual effect)

• Tap water & bottled water

endocrine disrupters

. Direct effects:

Bind to hormone receptors

Alter the appearance of some genes

Changes in the level of produced proteins

2. Indirect effects:

Altering hormone production

Altering hormone transport

Altering hormone metabolism

DES (diethylstilbesteol)

Synthetic estrogen used by physicians to prevent

spontaneous abortion (1948-1971)

• Administered for early pregnancy until 35 weeks

• > 1million women took it between 1960-1970

Endocrine Disrupters and its health implication/ neurobehavioural implications

Feminization of males

• Change in sexual behavior

• Birth defects

• Altered time to puberty

• Cancer of mammary glands or testicles

• Thyroid dysfunction (example)

• Prenatal and early postnatal exposures

• PCBs (Polychlorinated biphenyls):

– Impaired learning in nonhuman primates

– Delayed psychomotor development

– Distractibility

– Poor IQ tests

• Organophosphates

– Brain development

chemical body burdens

Quantity of chemicals accumulated in the body

– Biomonitoring – “normal level”

– Blood and fat analysis

– Not stable over time

– Not distributed homogeneously in a body

– Not possible to detect if present in very low

concentrations

what can you do to reduce your body burdens?

organochrloine substances: dioxins, DDT, phthalate and Bisphenol A

Dioxins are?

Dioxins have no commercial

usefulness by themselves

• Formed during

– combustion process such

as waste incineration,

forest fires and backyard

trash burning

– manufacturing processes

such as herbicide

manufacture and paper

manufacture

Group of chemical compounds with similar

chemical structure

• One of the most toxic and most studied is

2,3,7,8- tetrachlorodibenzo-p-dioxin (TCDD)

DDT (dichloro diphenly trichloro ethane

Agricultural pesticide

• Typhus- lice control

• Malaria - widely used for mosquito control for 20

years before persistence appreciated

Travels long distances

• Found in every corner of the globe

• Global distillation, “Grasshopper

effect”

• Very persistent (POP)

• Bioaccumulation/Biomagnification

• Accumulates in fatty tissues of

people and animals

• DDT in breast milk

ddt in humans dropped when and how low are the levels, what occurs?

Levels in humans dropped in the past thirty years

• Low levels of exposure still occurs (seafood, crops

grown in contaminated soil, imported food)

• Targeted use for mosquito control in some less

developed countries with high malaria rates is

approved by WHO

Phthalate and disphenol A

Phthalate—chemicals used to make plastics plastic

• Bisphenol A (BPA) also used in production of plastics

• May move slowly into air or

into contents of containe

Health effects of phthalates and bisphenol-A:

– Endocrine disruptors

– Developmental effects in male lab animals and

male infants (reduced anogenital distance)

– Emerging evidence of link to obesity in lab animals

and people

Heavy metals are?

Metallic chemical element that has specifc gravity ususally more than 5g/mL

toxic in even low concetrations

Naturally occuring, extracted from the earth

wide environmental dispersion

tendency to accumulate in selected tissues

classifiation of metals

1. Class A: K, Na, Mg, Ca

• Macronutrients (essential for biological processes)

• Low toxicity

2. Class B: • Hg, Pb, Cd, Ti

• Nonessential elements

• Very toxic (form soluble organometallics)

3. Borderline: Cr, Cu, As, Co, Ni, Zn, Mn, Fe

   • Almost all micronutrients

   Toxicity:

   Class B > Borderline > Class A

what are mechanism of toxcity?

Blocking essential functional groups in

proteins or enzymes; proteins can not carry

anything

2. Displace other metals (class B, borderline)

3. Modifying the active conformation of

biomolecules (class B)

what are some coping mechanisms?

Resistance – species develop mechanisms not to uptake

metal (example Pb)

• Tolerance – the capacity of a species to withstand high

level of metals

– Internal detoxifying mechanisms

• Binding to non sensitive compound structures

• Metabolic transformations to less toxic forms (methylation of

As in marine biota)

– Can develop multiple tolerance - Cu, Pb, Zn, Cd

bioavailabiltiy of metals

Species of the metal - free ions (charged ions

Zn+2 are more bioavailable than Zno)

• Neutral species may be bioavailable,

important in complexes

• pH of water/soil

• Redox potential of solution

what are some routes of exposure?

Inhalation (dust or PM, fume, gas)

• Ingestion (soil, food, plants accumulate metals in roots)

• Through the skin

• Mostly accumulate in the liver, bones, and kidneys

• Damage the brain, kidney, and some carcinogens

• Hard to diagnose (symptoms are weakness, headaches,

and hypertension)

what is mercury?

Metallic form - in batteries, dental

amalgams, and thermometers

• In industries, in different forms

• Liquid in pure form - not significant hazard

• When volatilize very toxic

• Organic and Inorganic forms, both toxic

• Bioaccumulation (tuna fish)

• “MAD HAT-MAKERS SYNDROME”

• Tremor of the hands, excitability, memory

loss, insomnia, and sometimes delirium

• Sensitivity of fetal and infant nervous system

to low levels of Hg (mental retardation,

language, memory and neural problems if

mother is exposed during the pregnancy)

what are the wood preseervatives?

Chemicals that protect wood from rotting due to insects

and microbial agents and on that way prolong age in

service of wood products

• CCA-C (chromated-copper-arsenat

• Water borne preservative

what are the toxicity of CCA Components?

Form (speciation) of elements

• Soil and water characteristics

• Characteristics of organisms

Form (speciation) of Elements are?

Cr (VI) exists as anions, more mobile and toxic than

Cr (III) which exists as the cation;

• As (III) more mobile and toxic than As (V) both are

anions; organic form is less toxic than inorganic

form;

• Cu exists as cation

what are characterisitics of soil and water?

pH

– Organic matter

– Texture (clay, silt, sand)

– Fe, Mn, Al oxides

Soil as barrier against toxicity

negative and postives of plants are?

N: Combined Cr, Cu, and As (7000ppm) completely inhibited the

growth of beans, carrots and tomatoes (Grant and Dobbs, 1977)

• Carrots grown in soil with 1000ppm of Cr, Cu, and As (200ppm

As), contained twice the recommended limit for As in food

(Grant and Dobbs, 1977)

P:

• No influence of treated wood on growth and content of Cr, Cu

and As in tomatoes (Jin and Preston, 1993), and grapes (Levi et.

al, 1974)

Toxicity of As, Cu and Cr to Human

As –accumulate in nails, hair and skin, most dangerous,

carcinogen, linked to skin, bladder, lung, liver and kidney

cancer as well as immunosuppression, cardiovascular disease

and diabetes, at very low level can change hormone function;

• Cr – carcinogenic, linked to lung cancer, asthma, and ulcers;

• Cu -vomiting, diarrhea, stomach cramps, and nausea (drinking

water), liver damage (very young children under high dose),

not known to cause cancer or birth defects, and very toxic for

aquatic environment.