EESA10H3_Course_Notes.doc

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Department
Environmental Science
Course
EESA10H3
Professor
Jovan Stefanovic
Semester
Fall

Description
E UNDERSTANDING HEALTH EFFECTS OF ENVIRONMENTAL HAZARDS • Your environment is your health (but not the only factor influencing your health) • Genetic materials or parents providing you the genetic material • We can’t chose environment but we can change the environment • According to the WHO: “In its broadest sense, environmental health comprises those aspects of human health, disease and injuries that are determined or influenced by factors in the environment. • This includes the study of both the direct pathological effects of various:  chemical  physical  social environment (housing, urban development, land use and transportation) • Environment is everything that affect a living organism • Effect of environment on human health is so great  Air  Water  Soil  Manmade environment • Human population and consumption • Human alteration of Earth is substantial and growing • Protecting the environment has been a mainstay of public health practices since 1878 • Environmental factors responsible for  25 % of all preventable diseases  Diarrhea and respiratory infections heading in the list  Reach & poor  African Americans & Hispanic & Whites  Developed & developing countries • We uses resources faster than they can be renewed  trees, water, oil, coal – leaving footprint • We destruct the environment because we can make money, yet it is detrimental to our health • People try to protect environment because of diseases caused by sewage [Cholera] • Diarrhea biggest problem because drinking of contaminated water in developing country • Chemical hazards (chemical in air, water, soil & food) • Biological hazards (bacteria, viruses, parasites, allergens, animals such as bees and poisonous snakes) • Cultural hazard (unsafe working conditions, poor diet, drugs, drinking, driving, poverty) • Physical hazards (radiation, fire, tornado, hurricane, volcanic eruption, earthquake) AIRBORNE HAZARDS AND HUMAN HEALTH • Air pollution is formed naturally [forest fires, volcanoes that can be avoidable] and manufacture [burning fossil fuels] • Outdoor Air Pollutions:  Ground Level Ozone  (O 3  Summertime pollutants, time of day, seasonal climate  Good in stratosphere b/c stratosphere protects us from UV & does not form ground level  CONCERN: Bad on ground  Chemical w/ 3 oxygen combined  Transported over long distances – does not matter where it forms e.g. Asia & affect US in N. America  Lung damage (small airways) – lung disease  Shortness of breath, chest tightness, coughing & nausea 1  Irritate & damage eyes, nose, sinuses, & throat  People who exercise a lot outdoors  Volatile compounds w/ nitrogen = photochemical reaction, triggered by sun  During day concentration of ozone changes  Heat & sun lights (pollution) = high day, rush hour, summer time  Warm, sunny climate – photochemical elements [Mexico & Los Angelus]  Particulate Matter  Particulate found in the air (dust, soot, smoke & liquid droplets, aerosols, or solid particles)  Big & small (black, smoke or tiny)  Vehicles, factories, construction sites, tilled fields, stone crashing, burning, different industries  Some formed in the air  Serious health effects b/c associated w/ acidic material  PM 10 – bigger particles remain in upper (mouth, lungs)  PM 2.5 – particles smaller than 2.5 can be transported through smaller part of lungs (small airway)  Carbon monoxide  You can be exposed to it & not know  Odourless, colourless gas  Can be indoor & outdoors  Incomplete burning of carbon containing fuels  Fire houses that are poorly ventilated, heaters, woodstoves, gas stoves, fireplaces, water heaters, automobiles, exhaust, tobacco smoke  1000 pple die each year in the USA as a result of CO poisoning  Sometimes symptoms are confused w/ flu or food poisoning  Foetuses, infants, elderly, & pple w/ heart & respiratory illnesses are at high risk for adverse health effects  Health effects are: o Interferes w/ delivery of oxygen in the blood to the rest of the body – higher affinity of haemoglobin then oxygen (200x) o Worsens cardiovascular conditions o Fatigue o Head aches o Weakness o Confusion o Disorientation, loss of coordination (we leave area exposed even if we realize CO exposure) o Nausea, dizziness, death o Concentration increases symptoms get worse & usually result in death  To prevent: o Never leave a car engine running in a shed or garage or in any enclosed space o Proper selection, installation, & maintenance of appliance o Correct use of products o Good ventilation o Use CO detector  Nitrogen oxides  Form in any type of combustion process  Involve in formation of ground level ozone  Form nitrate particles, acid aerosols  Contribute in formation of acid rain  Transported over long distances  Nitrogen reacts in air – salts  Nitrogen can dissolve in water b/c acids are formed  Sulphur oxides 2  Burning of coal [highest form of SO], extraction of metals from ore  SO 2issolve in water vapour to form acids  Acids react w/ o/ gasses & particles & form sulphates  Respiratory illnesses, aggravates existing heart & lung diseases, enlargement of heart  Transported over long distances  Different types of ore, extraction of lead = high level of SO  In process high levels are emitted in air  Dissolves easily in water = forms acids  Can interact w/ suspended particles & form solids (sulphates)  Lead  Metal  Vehicles & industrial sources  Leaded gasoline  Particularly effect young children  Deposit on soil & water  Children accidently can eat solid  High ways • Any burning combustion process is pollution • All are regulated by Clean Air Act USA & strict threshold placed on these pollutants • Indoor Air Pollutions:  Can be controlled  Contains 2 – 5 times higher concentration of hazardous pollutants than outdoor air  Buildings more airtight to conserve energy, in adequate ventilation  Pple spend about 90% of their time indoors  Children, pregnant women, elderly, pple w/ chronic illnesses are more vulnerable • Sources of the pollutants are:  Building materials & furnishing  Asbestos insulation  Wet or damp carpet  Furniture made of certain pressed wood products  Cleaning products & air fresheners e.g. Lysol: can kill germs  Personal care & hobbies, cleaning products  Pesticides  Cooking – burning toast  Bathing – chlorine evaporates if too hot  Heating (combustion of oil, coal, wood)  Radon – radioactive gas  Smoking  Outdoor pollution  Tencillon: coated on pens  Pethions: exposed to high temps, it can emit 30 kinds of gasses & some are carcinogens • Hard to detect by our senses • Symptoms are similar, need years to develop • Headaches, tiredness, dizziness, nausea, itchy nose, scratchy throat • Cancer, asthma – if concentration is high • Pple think they have these symptoms from something • Symptoms can develop after many years • ASBESTOS  Group of six different fibrous minerals  Have separable long strong & flexible heating resistant fibres 3  Is common for fibrous material  Are possible to separate, strong & flexible & heat resistant fibres  Fibres are used for gloves & protective wear  Fibrous asbestos  Used in:  Building materials (roofing shingles, ceilings & floor tiles, paper products & asbestos cement products)  Friction products (automobile brake & transmission parts)  Heart resistant fabrics, packaging & coatings • Causes cancer • Asbestos Exposure  Do not evaporate into air or dissolve in water, does not break down  Fibres & particles may remain suspended in the air & carried long distances  Not able to move through soil  Where it found depends on characteristics  Does not break down in chemical compounds • How might I be exposed?  All to low levels, all the time  Pple working in some industries  Pple living near those industries  During demolition work & remodelling of house  From drinking water (natural or asbestos containing cement pipes) • Health effects of asbestos  Affect the lungs & the membrane that surrounds the lungs  Asbestois car-like tissue, not general public  Difficulty breathing, often cough , heart enlargement, lead disability & death  Respiratory illness  Plaques in the pleural membranes – the tissue is unable to expand & contract, breathing can become painful or impossible  Heart: blood flow to lungs can be impaired & cause the heart to enlarge or fail  Asbestos fibres in the alveoli can cause cancer & prevent exchange of oxygen & carbon dioxide btw the lungs & red blood cells  Increase of cancer (lung, stomach, esophagus, pancreas, kidney)  Risk increase w/ smoking [250x]  Not related w/ birth defects  Low levels can be measured in urine, feces, mucous or lung washings - test done by • Exposure to asbestos is not an autonomic death sentence. Many factors determine health effects & how severe they will be • Factors include how many fibres entered the body, how long the exposure of the material, if the material was inhaled or consumed in food or drink • Fibres enter the body through the nose & mouth by drinking or inhalation • FORMALDEYHDE  Can evaporate under room temp  Volatile organic compound (VOC), naturally occurring gas, colourless gas, strong smell  Become a gas at normal room temperature  Also released by burning wood & natural gas, by cigarettes  Carpet  Product of burning process  Glue or adhesives in press wood products (particleboards, MDF, plywood)  Preservatives in some paints and cosmetics  Coatings that provide permanent press quality to fabrics & draperies 4  Finish used to coat paper products wall paper  Certain insulation materials  Some fabrics • Health effects of Formaldehyde  Watery eyes, burning sensation in the eyes, nose & throat  Nausea, coughing  Chest tightness  Asthmatic reactions  Cancer  Some pple very sensitive & some don’t experience any symptoms • MOLD  Need moisture, do not need standing water, high relative air humidity  Bathrooms, kitchens  Gym areas  Locker rooms  Leaky roof areas  Damp basements  On or w/in wood, paper, carpet & foods  The way to control indoor mold growth is to control moisture (maintaining the relative humidity btw 30 – 60%  Often undiscovered  Water is not necessary to form mold  Any surface w/ moisture  Known by unpleasant smell • Health effects of mold  Major source of indoor allergens  Produce toxins  Produce irritants • SECONDHAND SMOKE  Contain 4000 compounds (CO & formaldehyde), 40 are carcinogens  Each year 3000 lung cancer deaths in non-smoking adults in USA  Eye, nose, throat irritation  Affect the cardiovascular system  Higher risk of asthma, pneumonia, ear infection, bronchitis in children  Second hand smoke is more harmful then direct smoking • AIR DUST AND INDOOR AIR QUALITY  Heating & cooling systems of force air systems – high amounts of dust  Dust particles, pollen or o/ debris  Duct cleaning service providers WATERBORNE HAZARDS & HUMAN HEALH • The earth is a water planet • Water covers 71% of Earth surface – not all is available for consumption b/c not as much fresh water • Mostly salt water • No species can do w/hout water • Sculpting the Earth’s surface • Moderating climate • Removing diluting wastes & pollutants 5 • Waster is used for agriculture • Geomorphology – water changes shape of Earth: soil erosion • Mind winter & not too hot summer • Water universal solvent • Total ocean & lakes 2.6% available • In 2.6% ice capes & glacier, thus not readily available & it is ground water: can’t be used more than it can be replenished • 0.014% readily available • 1.984% ice caps & glacier • Ground water 0.592% • 0.007 % lake • 0.0001% Biota & Rivers • 0.001% Atmospheric water vapour • 0.005% salt moisture • In Canada most water is used in power plant 64%  Industry 15% Public 12%  Agriculture 9% • US & China use most water for agriculture 41% & 87% respectively • Us & China don’t use much water for power plants 38% and 0% respectively • US water use – Agriculture  38% power-plant cooling  11% Industry  10% Public • China water use – Agriculture  7% Industry  6% Public • Canada use of water  35% showering, 30% Fishing, 20% laundry, 10% Drinking, 5% Cleaning • One out of six pple do not have regular access to clean water • Diarrheal deaths kill over 2 million children annually • Africa, Asia • Pple have to walk hours to get water & if many not even get clean water • The #1 death in kids – diarrhea • DRINKING WATER:  Annual reports on local drinking water quality  Naturally pure water (is not pure, has minerals) & distil water(has minerals)  Natural content of minerals in water  Surface water – in urban areas mostly from rivers, lakes & reservoirs (under 6 US states) – decreasing b/c not replenished  Ground water – in rural areas (wells)  Check water taps everyday & provide annual report on it – every municipality  Water is not pure – must have some minerals • DRINKING WATER TREATMENT:  Waters from lakes & reservoirs:  Settling tanks – leave water for particles to settle  Addition of coagulants – dirt & contaminants from clumps that settle to the bottom of the tank – coagulant chemicals make clumps of smaller particles & settle to the bottom not good for virus  Filtering – bacteria, microbes, protozoas, virus  Chemical treatment (disinfection, granulated activated charcoal – organic contamination , ion exchange resins- soil has minerals (reaction occurs) = filtered , reserve osmosis – metals & inorganic contamination)  Ground water:  Naturally filtered  Less organic matter  Often does not need any treatment  Soil works as a filter CHEMICAL TREATMENT OF DRINKING WATER 6 • Chlorination of Drink Water: Its Benefits & Risks  Chlorine – organic matter  Chlorate  Hypo-chlorate  DBP – so complicated holamethane these chemicals have adverse effect on health, but data not completely clear – need more data  Carcenogenic, cause, spontaneous abortions  Kills allergens • Contaminants in Drink Water  EPA (Environmental Protection Agency) – US sets standards for approximately 90 contaminants  Microbes o Fecal Coliform and E.coli bacteria: contamination w/ human & animal wastes, diarrhea, cramps, nausea headaches, renal failure, coagulation disorders o Salmonella typhi: typhoid fever (high fever, abdominal pain, constipation) o Shingella sp.: more severe abdominal cramping w/ blood & mucus in the stool, hydration o Vibrio cholerae: life threatening, rice-water stools o Norwalk viruses, enteroviruses, adenoviruses: diarrheal illness o Hepatites A: a live inflammation  doesn’t affect gasteral intestinal tracts o Cryptosporidium: parasite that enters lake & rivers through sewage & animal waste o Giardia lamblia: enters lake & rivers through sewage & animal wastes, diarrhea, vomiting, cramps  Radionuclide o Alpha emitters – breath & drink water, diluted in water o Beta/photon emitters o Combined radium 226/228 o Radon gas o Damage DNA [changes & transforms], increase risk of getting cancer  Inorganic contaminants o Arsenic – found in ground water, after many years of drinking, possibility of skin damage, problems w/ circulatory system, higher risk of getting cancer o Fluoride – added to promote dental health, in excess cause bone disease o Lead - lead pipes are banded, in kids causes brain/mental retardation, old houses can expose it and it can be dangerous, cause arthritis o Nitrates – mineral fertilizers, inhibits red blood cell’s ability to transfer oxygen, methemoglobinemia – oxygen starvation, cyanosis (bluish discolouration of skin & lips), spontaneous abortion & neural tube defects, birth defects, brain & spinal cords, In lake Ontario – agricultural plants nitrates change into nitrites in the water & this is more toxic Nitrates changing to Nitrite occurs in the body and water – depends if we bacteria is in water for the process to occur o The temperature of the water – warmer the water the faster the transformation e.g. spinach o Walkerton, example of (E.coli) – government hired water experts, checked but didn’t warn public, no one was immune to this o India & China - naturally occurring fluoride, not enough water, government tried to get ground water, sever health problems o Bangladesh, India, China – naturally occurring arsenic, was naturally contaminated w/ arsenic & fluoride, so far no solution  Synthetic Organic Contaminants (including pesticides & herbicides) o 2, 4,- D o Atrazine o Chlorodane o Lindane o PCB’s 7 o Pentachlorophenol o DDT – is persistent & stays in the env for a long time o Chlorinated hydrocarbons o Dieldrin o Stertility, cancer, some have little acute toxicity but effect endocrine system  Volatile organic compounds (VOC) - Industrial o Benzene o Dichloromethane o Styrene o Toluene o Vinyl chloride o Xylenes o In developed countries, almost prevented into entering water system but still exists  MTBE (Methil-Tert-Butly Ether) o Fuel additive, replace the use of lead & octane enhancers o Used to reduce carbon monoxide & ozone levels caused by auto emission o Leaking underground tanks, to some extent from air deposition o Fuel additives increase octane # o Used for gasoline o No big risk in air or water  Disinfection byproducts o Form when disinfectants react w/ naturally occurring organic & inorganic matter & inorganic matter in water o Triholomethanes: excess over many years cause liver, kidney, or central nervous system problems, increased risk of getting cancer o Haloacetic Acid: increased risk of getting cancer o Bromated: increased risk of getting cancer o Chlorite: children could experience nervous system effect, some pple may experience anaemia  Drinking Water from Household Wells  Make sure that well is built properly  Check the water regularly  Natural contaminants (radio nuclides, nitrate & nitrite, heavy metals, fluoride)  Improper use of fertilizers, pesticides, animal manure  Poorly located septic system  Leaking underground tanks  Improper disposal of wastes  Chemical spills at local industrial sites  Noticeable Problems  Visible o Scum from calcium salts o Turbid water from dirty, clay or rust o Green stains on sink caused by high acidity  Tastes o Salty taste from high sodium content o Soapy taste from alkaline minerals o Metallic taste from acidity or high iron content o Chemical taste from industrial chemicals  Smells o Rotten eggs odour from hydrogen sulphide gas or bacteria o Detergent odour o Gasoline smell 8 o Methane gas smell from organic matter in water o Chlorine smell from excessive chlorination  Swimming Hazards  Beach pollution  Trash  Microorganisms  Sore throats  Diarrhea  Some serious poisoning CHEMICAL HAZARDS & HUMAN HEALTH • Chemical Hazards  Endocrine disruptors  Chemical body burdens  These two overlap endocrine disruptors can also be chemical body burdens & vice versa  Both can be industrial  Biggest problem we don’t know how these chemicals affect human health  Most conclusions are assumptions or are from experimental animals  Endocrine glands produce hormones  Hormones regulate many processes in the body using tiny amounts  Hormones are carried throughout body through receptors or chemical • Endocrine Disruptors: 9 1. Direct Effects:  Similarity btw hormone & pollutant (endocrine is disruptor )  Receptor doesn’t recognize if it is a hormone or endocrine disruptor & binds to the endocrine disruptor  Alter the appearance of some genes  Changes in the level of produced proteins  Carry endocrine disruptor & hormone  Some genes alter b/c binds to DNA  Gene regulate production of different protein, b/c of change there is change in production 2. Indirect Effects:  Altering hormone production  Altering hormone transport  Altering hormone metabolism  Adverse effects are not as much visible in fetus than adults  Changes in hormones affects fetus –  Thyroid hormone affects mental development & brain development of foetuses • DES (diethylstilbesteol)  Pregnant mother exposed to endocrine disruptors not much affects seen on her health but changes in life of daughter and sons, wait 20 – 30 years to see adverse effects  Synthetic estrogens used by physicians to prevent spontaneous abortion (1948-1971)  Administered for early pregnancy until 35 weeks  1million women took it between 1960-1970  Daughters whose mothers took DES have increased incidents of :  Reproductive organ dysfunction  Abnormal pregnancies in daughters  Reduction in fertility  Immune system disorders  Adenocarcinoma  Because of lack of knowledge  Mothers did not suffer that much • Endocrine disruptors – Health Implications  Feminization of males  Abnormal sexual behaviour  Birth defects  Altered time to puberty  Cancer of mammary glands or testis  Thyroid dysfunction – PCBs affect functions of thyroid glands • Endocrine disruptors – neurobehavioral effects Prenatal and early postnatal exposures (breast milk)  PCBs affects:  Impaired learning in nonhuman primates  Delayed psychomotor development  Distractibility  Poor IQ tests  Organophosphates – affects Brain development • Chemical body burdens  Caused by industrial chemicals  Quantity of chemicals accumulated in the body  Not stable over time in the body – partially metabolized, degraded not much, excreted through urine o/ ways of excretion & not distributed throughout body  Not distributed homogeneously in a body – accumulated in nails, skin, hair, kidney  Arsenic accumulates in hair & nails b/c of this some organs have high concentration so have low 10  Detection – no good technique to detect these chemicals in ppb  Technique ICP – good technique to detect metals,  All techniques have detection limits, can’t detect lower levels  Government puts money in to monitor these levels in the population - compare two groups high exposure & low exposure & figure out the adverse health effects of level Biomonitoring – “normal level” • Organochlorine Substaces  Dioxins  Have o commercial usefulness by themselves  Formed during: o Combustion process: such as waste incineration, forest fires, & backyard trash burning o Manufacturing process: such as herbicide manufacture & paper manufacture  Groups of chemical compounds w/ similar chemical structure  One of the most toxic & most studied is 2,3,7,8 – tetrachlordibenzo-p-dioxin (TCDD)  Has four chlorine atoms  Position of chlorine creates its characteristic  More chlorine, more toxic  At low levels in food: stored in animals, plants, crops, milk, meat, grain  Very slowly removed from the body  Accumulate in fat tissue  Effect of constant exposure to low levels is not known  Focal point for ongoing research (the molecular & cellular mechanism)  Persistent  Lipophilic – like fat/accumulates in fat  Accumulates in animals more b/c they have more fat  At high levels it can be toxic o Cause cancer in laboratory animals & humans, mechanism is not known o Alter reproductive developmental & immune functions o Increased heart disease & diabetes o Immune suppression o Study in mice showed ability to cause birth defects (tertogenicity) – birth defects  Affect cells in similar way as hormones such as estrogens o Binds to protein (Ah receptor) present in cells o Than receptor can bind to DNA & after the appearance of some genes o This can lead to changes in the level of specific proteins & enzymes in cell o b/c American consume a lot of beef or meat o beef  dairy  milk  chicken  pork  fish  egg  inhalation  soil  water o genetics, general health, age depend for low or high level  Chloroacne  Causes skin problems s 11  Is reversible  Victor Yushchenko – President of Ukraine before & after dioxin poisoning  DDT (C H C14)9– 5ichloro-diphenyl-trichloro-ethane  Control diseases such as malaria & typhus  Breakdown products – DDE & DDD th  Discovered end of 19 century  Wasn’t used until the end of WWII  Used to kill vectors e.g. mosquito & lases  Travel long distances  Found in every corner of the globe  Global distillation, “Grasshopper effect” o Are volatile o Warmer climate: evaporate & carried by wind o Mild climate: condensate & remain o Fat tissue – higher temperature o Found in higher concentration in mammals in N.America  Very persistent  Biomagnifications  Accumulates in fatty tissues of people & animals  DDT in breast milk – infants b/c special diets in polar region [eat seals, fish] 4 – 5X greater than in Toronto  Winston Churchill said it was a miracle b/c of the lack of knowledge that existed it saved soliders  Biomagnify: concentration increases through food chain  Top: higher concentration [human]  Levels in humans dropped in the past thirty years b/c of ban  Decreased constantly b/c persistant  Low levels of exposure still occurs (seafood, crops grown in contaminated soil, imported food)  Still in use for prevention of malaria – some not contaminates b/c no better pesticide or chemic to fight it  Used locally no agricultural use  In developing countries increase in malaria b/c less DDT use  WHO: saved 5 million lives from malaria  High risk area DDT good b/c decreases economic loss  Health affects: o Can damage liver o Carcinogen – linked to breast cancer o Reduced reproduction success o Damage to reproductive system o Damage to the liver o Endocrine disruptor – mimicking estrogenic compounds in the body o Chronic long term exposures effect nervous system 12  DDT restrictions: o Used sometimes in epidemics o Us still exports to o/ countries o Ban in US in Ban in the US in 1972 except for public health emergencies. Small amounts were used until 1980. In 1991, the US exported 92 tons of DDT o In at least 26 countries, DDT is completely banned, and in 12 others it is severely restricted. In these latter cases, it is permitted for use by government agencies for special programmes, usually involving vector control programmes o Total Bans:  Canada 1985  Chile 1985  Cuba 1970  Liechtenstein 1986  Korea 1986  Poland 1976  Singapore 1984  Switzerland 1986 * Soviet production and use continued secretly after the 1970 ban. In some cases, DDT production even increased HEAVY METALS & HUMAN HEALTH • Used in products  deposited or reused (underground) • Spreads in air, water, food • Naturally occurring extracted from the earth in ore • In different forms: extracted/mined, incorporated, salts • Wide env dispersion • Tendency to accumulate in select tissues • Toxic in even low concentration 3 • No agreed description – specific gravity, some say: 7 g/cm density heavier then this is a heavy metal • Different definitions- all elements w/ metallic characteristics, density of elements, atomic weight • Metals (arsenic) considered heavy metal • Trace metals found in low concentration • Heavy metals are toxic (most) – dependent on concentration • Accumulation affects organs • Classifications of Metal: 1. Class A:  Needed in significant amounts  K, Na, Mg, Ca, Al – cations: positive charge  Macronutrients (essential for biological processes)  Tend to form ionic bond  Low electronegativity (tendency to lose rather than acquire electrons)  Low toxicity  Forms ionic bonds – borrow electrons, attracted by cation & anion forces 2. Class B:  Hg, Ti, Pb, Ag, Au  Nonessential elements  Tend to form covalent bond  High electronegativity (tendency to acquire rather than lose electrons)  Very toxic (form soluble organometallics) 13  Interfere in the process of our bodies 3. Borderline:  Cr, Cu, As, Co, Ni, Zn, Mn, Fe  Micronutrients • Toxicity: Class B  Borderline  Class A • Mechanism of Toxicity 1. Blocking essential functional groups such as proteins or enzymes, proteins can’t carry anything  Protein receptor carry hormone, metal attaches to protein, blocks protein function 2. Displace other metals (class B, borderline)  Necessary metal – o/ toxic metal attach 3. Modifying the active conformation of biomolecules (twisting of molecules) (class B)  Organic compound ,transforms • Coping Mechanisms  Resistance – species develop mechanisms not to uptake metal (example Pb)  Does not take place in humans but in plants  Tolerance – the capacity of species to withstand high level of metals  Internal detoxifying mechanisms – not that toxic/ sensitive  Binding to nonsensitive compound structures – forms organic form of arsenic  Metabolic transformations to less toxic forms (methilation of As in marine biota) – get less toxic form  Can develop multiple tolerance- Cu, Pb, Zn, Cd – human & plants  Threshold – small amounts can be tolerated  Non threshold – small amounts cause adverse health effects • Bioavailability of metals • Toxicity Depends on:  Species of the metal - free ions (charged ions Zn+2 are more bioavailable then Zn)  Neutral species may be bioavailable, important in complexes  pH of solution – stomach: acidic below 7, btw 4 – 5 more toxic & bioavailable, above 7 less bioavailable & toxic  Temperature – warm more available  Redox potential of solution – amount of oxygen & soil/water – low level – toxic (less 0), high level – less toxic (more 0)  Not everything is bioavailable  Form- ionic, organic?  Element  Arsenic less toxic in organic • Routes of Exposure  Inhalation (dust or PM, fume, gas)  Ingestion (soil, food, plants, accumulate metals in roots & leafs) – carrots a leafy food thus high concentration vs. potatoes are safe  Through the skin  Mostly accumulate in liver, bones, kidney  Damage the brain, kidney, some carcinogens  Hard to diagnose (symptoms are weakness, headache, hypertension) • Mercury (Hg)  Toxic in any form  Changes form quickly  Metallic form of is toxic  Metallic form - in batteries, dental amalgams(fillings), industry, agriculture, thermometers, fish 14  In industry in different forms  Liquid in pure form, not significant hazard  When volatile very toxic  Organic and Inorganic forms, both toxic  Bioaccumulation (tuna fish) – by accumulation  Tremor of the hands, excitability, memory loss, insomnia, sometimes delirium  Sensitivity of fetal and infant nervous system to low levels of Hg (mental retardation, language, memory and neural problems if mother are exposed during the pregnancy)  Pregnant woman should avoid fish particularly tuna  Can evaporate/liquid  Can tuna – adults max 1 – 2/ weeks, child max 1/month, pregnant women should avoid  No studies agree or disagree ENVIRONMENTAL IMPACT CCA WOOD PERSERVATIVES • Chemicals that protect wood from rotting due to insects & microbial agents & on that way prolong age in service of wood products • Is a pesticide • Most used & most effective is CCA-C (chromate-copper arsenate)  Contents: 47.5% - CrO ,318.5% - CuO, 34% - As O2 5  Water borne preservative  Used to stop decay, preserves life therefore reduce # of trees cut  Dissolves in water & treated in water  Fixation process – chemical reaction of Cr, Cu, & As salts w/ wood components – forms insoluble salts  After treatment left to rest – fixation time • Product of CCA treated  100% of residential lumber  70% of all wood products – change in colour to green is Cu oxidizes  Important industry in N. America (annual gross sales in USA of around 3.91 x 10 ) • Positive Aspects of CCA wood preservation  Long efficiency: 50 years & more in ground contact  Excellent results in marine use  No odour to wood  No problems w/ corrosion  UV resistant  Simply quality control  Reasonable price  Reduce needs for cutting forests  Used for many purposes • Environmental concerns  Leaching  Soil o Ingestion o Inhalation o Plants o Soil organisms o Ground water  Aquatic system  Rub on hands (ingestion) • Toxicity of CCA components 15  Form (speciation) of elements  Cr (VI)-6 exists as an anions, more mobile & toxic than Cr (III) which exists as the cation  As (V) – 5 less mobile & toxic than As (III) both are anions; organic form is less toxic then inorganic form  CU exists as cation  Soil & water characteristics  pH  organic matter  texture (clay, slit, sand)  Fe, Mn, Al oxides  CEC  Chemical reactions  Soil as barrier against toxicity  Absorbs chemical  Prevent to re-enter in ground water & soil  Characteristics of organisms • Plants  Combined Cr, Cu & As (7000ppm) completely inhibited the growth of beans, carrots & tomato (Grant & Dobbs, 1977)  Carrot grown in soil w/ 1000ppm of Cr, Cu & As (200ppm As), contained twice the recommended limit for As in food (Grant & Dobbs, 1977)  No influence of treated wood on growth & content of Cr, Cu, & As in tomato (Jin & Preston, 1933), & grape (Levi et. Al, 1974) • Toxicity of As, Cu & Cr to human  As: accumulates in nail, hair & skin, most dangerous, carcinogen, linked to skin, bladder, lung, liver & kidney cancer as well as immune suppression, cardiovascular disease & diabetes, at very low level can change hormone function; physical & mental illness  Cr: carcinogenic, linked to lung cancer, asthma, ulcers  Cu: vomiting, diarrhea, stomach cramps, & nausea (drinking water), liver damage (very young children under high dose), not known to cause cancer or birth defects, very toxic in aquatic env • Present situation  Wood scientists vs environmental scientists  Best product for wood b/c protects business says it has no effect vs objective (CCA)  CCA used industrial  2000 – no residential use  Before that in the US  Phased out for residential use in Dec. 2003  No strong evidence  Debate exists • Arsenic as a popular way of poisoning pple since the Middle Ages  George III of Great Britain (1738 – 1820) – found in hair  Movie “Arsenic & Old Lace” (1944, acting Cary Grant)  How Napoleon Bonaparte died (pigment Emerald Green – Van Gough) – paint wall  Clare Boothe Luce (1903 – 1987) the American ambassador to the Vactican – arsenic in blood CCA (Chromated Copper Arsenate) wood preservative: “Protector” of forest vs. carcinogenic chemical Silvija Stefanovic Wood preservatives are used to protect wood products from decay and in that way to prolong their age in service. In the same time, wood preservatives reduce needs for forest cutting and support concept of Sustainable Forest Management. 16 One of the preservatives with very effective protective characteristics is CCA (chromated copper arsenate). For that reason, 100% of residential lumber and 70% of all wood products were treated with CCA at last decade. Chromated Copper Arsenate (CCA), water borne preservative, was developed in 1933 and has been widely used throughout the world since then. During that period CCA has proven its ability to adequately protect wood from fungal and insect attack. The CCA-treated wood is used in applications such as utility poles (especially electric and telephone), wooden playground equipment, garden projects, marine piles etc. Depending on the relative proportion of metals, there are three waterborne formulations designated as CCA types A, B, and C. In North America, CCA-C is used almost exclusively. This type contains 47.5% Cr03, 18.5% CuO, and 34% As2O5. When they are dissolved in water, the solution becomes very acidic with a pH of about 1.8. All of these inorganic components combine together become almost insoluble when impregnated into the wood. This is known as fixation. When the active ingredients of CCA become fixed into the wood, they become resistant to leaching. However, some portion of the CCA components is not completely fixed when wood products are placed in service. This causes the inorganic compounds to be leached into the soil and water. Amount of the active ingredients of CCA leached from wood constructions in service depends on rainfall, pH of aqueous solution, wood species, etc. In that way, soil and water can be contaminated with As, Cu and Cr. Arsenic and Chromium are known as carcinogenic elements, and poses chronic and acute environmental health risks. Cooper is less toxic for humans, but is highly toxic to aquatic fauna and flora. Concentration of As, Cu and Cr in CCA leachate is very low but during the time can potentially accumulate in soil in doses harmful for organisms. Soil characteristics such as pH, organic matter, texture, redox potential, Fe, Mn and Al oxides, CEC etc. play major role in fate and chemical behavior of these elements. Soil as effective barrier and buffer against toxicity, can be very useful in CCA contaminated soils. Consequently, Cr, Cu, and As cycling can be slowed and the output portion of these elements from soil system is certainly different (quantity and quality) than input portion. However, the great number of soil characteristics and their variation among different soil types make this problem difficult to understand. Also, amounts of CCA preservative components in soil water and potential contamination of ground water are not known. The capacity of plants to accumulate CCA components is limited. Excess of trace elements in soil, even among the essential micronutrients (such as Cu), could results in phytotoxicity. Factors such as plant species, plant cultivars, plant part and age, ion interactions, management practices, soil and climatic conditions can affect the ability of plants to accumulate CCA components. Until now scientists didn’t get final answer about toxicity of CCA. Results greatly vary depends who conduct environmental testes, wood or environmental scientists. Both of them have very strong arguments to support their opinion. Despite of conflicting research data CCA is going to be phased out for residential use bDec.2003. General public had great influence on CEPA to promote this decision. In future period slowly replacement of CCA by alternatives such as: ACQ-D (ammoniacal copper quaternary), CBA (copper azol), ACC (acid copper chromate), and CC (copper citrate) can be expected. There is relatively little information available about the environmental impacts of these new preservatives in comparison with CCA. RADIATION & HUMAN HEALTH • We can’t escape radiation 1. Background Radiation  Found in the woods  Natural radioactivity in the Earth & cosmic rays from outer space  Produced naturally  Ca not be controlled 2. Manmade radiation  Electronic products  X-ray machines  X-ray diagnostic 17  Television sets  Microwave ovens  Radar devices  Lasers  Can be controlled  Can be protected from • Ionizing Radiation Exposure to Public  Natural radiation consists of a total of 82% of measurable radiation  Man made is 18% • Radiation & Human Health  Ionized radiation  Has so much energy that it can change an element – pushes electrons away  Short way lengths  Radioactive material that decay spontaneously produce ionizing radiation o Strip away electrons from atoms (create two charged ions) o Break some chemical bonds  Alpha beta particles, gamma & x-rays (differ in the amount of energy they have)  Harmful to human health  Natural decay – produce ion radiation, break chemical bonds 18  Health effects from exposure 1. Stochastic health effects (acute) o Long term, low level of exposure o Increase levels of exposure make these effects more likely to occur but do not influence the type or severity of the effect o Hard to detect & treat b/c not 100% known o Cancer: uncontrolled growth of cells, damage at the cellular & molecular level o Changes in DNA – mutations, teratogenic (most sensitive in 8 – 15 week of pregnancy, smaller head or brain size, poorly formed eyes, mental retardation), genetics (passed from parent to child) 2. Non-stochastic health effects (chronic) o Short term, high level exposure o Increase levels of exposure make these effects more severe o Cancerous health effects, Yes or No o Radiation sickness (nausea, weakness, hair loss, skin burn or diminishing organ function, premature aging, death) 2 – 3 months  Nuclear Power plant accidents o Three Mile Island, Pennsylvania, 1973 o Chernobyl, former Soviet Union, 1986 – Ukraine changed to vegetation o Chernobyl accident had 10 – 20 time exposure than Three Miles Island’s accident o Nagasaki, Hiroshima o After effects no longer health effects b/c low o The effect of different doses of radiation on human body after acute, whole-body exposure  Some scientists thinks that low levels of radiation are beneficial  How do we know radiation causes cancer? o In 1910 observed that radiation cause skin cancer o Japanese atomic bomb blast survivors o Uranium miners 19 o Medical treatment o Children more sensitive b/c they are growing rapidly  Chemical Properties of Radionuclides o Chemical properties determine where health effects occur o Organs can not distinguish btw radioactive & non-radioactive forms of element 1. Radioactive iodine in thyroid 2. Calcium, strontium -90 & radium0226 accumulate in bone 3. Some form that no radionuclides e.g. lead same chemical properties 4. System does not recognize if radioactive or normal function, can’t distinguish btw two  Radon – radioactive gas o Natural radioactive breakdown of uranium in soil & water o Causing lung cancer o Odourless, colourless gas o Indoor air pollution o The second leading cause of lung cancer in the US today – 1 is tobacco o Carcinogenic  Non ionized radiation  Long wave lengths  Has lower energy does not mean it is not harmful  Harm is not harmful  Microwave Radiation: o used to detect speeding cars o used to send telephone & television communications o used to treat muscle sourness o used to dry & cure plywood o used to raise bread & donuts o used to cook potato chips o used for microwave oven o form of electromagnetic radiation & sun o used in cooking b/c they are absorbed by foods o pass through glass, plastic, paper o reflected by metal o microwaves bounce back & forth w/in the metal interior until they are absorbed by the food o water molecules in food vibrate, producing heat that cook the food o food is not radioactive or contaminated o cook for outside, heat conduct to inside o cook unevenly o doctors/nurses say not to reheat baby formula b/c milk does not heat evenly, bacteria stay & can duplicate in milk o more energy efficient b/c food cooks faster & energy does not heat the env o may keep more vitamins & minerals than conventional cooking b/c cooks faster w/hout needing water o glass, plastic is not heated, but can become hot from the heat of the food o some plastic is not microwave safe  burning, overheating, release chemicals o metal pans & aluminum foil not in microwave  Microwave Oven Safety Standards o Implemented in 1971 o Leaking can not be more than: 5 milliwatts of microwave radiation per square centimetre at approximately 2 inches from the oven surface o This is far below the level known to harm pple o The level decreasing w/ the distance from an oven 20 o Two independent interlock systems o Everyone must have a label stating that it meets standards safety  Microwave Ovens & Human Health o How the low levels affect the human health is not known o Animal research – genetic changes, immune response o Heat human tissue o The lens of the eye is very sensitive to intense heat o Microwaves can cause cataracts o Painful burn o Temporary sterility (alter or kill sperm)  Smoke Detectors & Alarms o Ionisation chambers – small amount of radioactive material encapsulated in a metal chamber imp produce electron o Low but steady electrical current o Smoke disrupts the current & trigger the detector’s alarm o Very small radiation until source stay in detector apparatus  Television Radiation o X-rays produced when electrons strike barrier while travelling in the vacuum as in a TV tube o Potential x-ray radiation o Most TV sets not give off any measurable level of radiation o No evidence of human injuries o Effects of low levels exposure not known o TV sets in 1966 take care of human stay 1 – 1 ½ metres o Make sure that your TV set meets the standards on emissions  Electric power lines o Local & regional o Generation, transmission & use of electric power o Electromagnetic fields surround any electrical device o Very low frequency o Planet earth also produce magnetic fields  Cell phones: Are they Safe? o Brain cancer outside of brain of most side used o There is no proof that wireless phones are absolutely safe o There is no scientific evidence that they cause any health effect o They emit low level radio-frequency waves, lower when in standby mode o RF energy is not great enough to cause ionisation of atoms & molecule  What are the results of the research done already? o Three large epidemiological studies have been published since Dec. 2000 o None of them demonstrated the existence of any harmful health effect o But none of them answer question about long term exposure o The angle at which the phone is held o Which model is used  Electromagnetic Hazards & Human Health o Health risk from EM fields is weak 1. Laboratory studies: no consistent pattern of biological effects is seen 2. Epidemiological studies: small risk of leukemia o Increase cancer risk from magnetic field, not for the electric field o Workplace exposure (electric utility workers, railway engine drivers, conductors) 3. Clinical study: studies w/ human volunteers o Heart rate – inconsistent effect o Sleep pattern – poor & disruptive sleep 21 o Hormones – inconsistent effect o Immune system – inconsistent effect o Blood chemistry inconsistent effect BIOLOGICAL HAZARDS & HUMAN HEALTH • Biological Hazards [overlap w/ food borne illness]  Nontransmissible diseases (cardiovascular, cancer, diabetes, asthma)  no proof that these can be transferred from human to human  cardiovascular – heart disease caused by smoking or artery clog  cancer – many different types, no one cause  diabetes  asthma – many new chemical, agents are applied, allergins  Transmissible disease (infectious agent, bacteria, viruses, protozoa)`  Growing germ resistance to antibiotics  High reproductive rate allow resistant quickly  Overuse of antibiotics – using antibiotics when not needed or used to often & next time it’s needed a resistance is created by bacteria b/c bacteria multiply faster & the mutation is multiplied  Antibiotics in food additives to boost livestock & prevent diseases also creates antibiotic resistances  Can be transferred from human to human  Can be cured by antibiotics only w/ bacteria not w/ viral  Bacteria  Tuberculosis o in 2004, mortality statistics included:  14.6 /5million chronic active [visible symptoms] TB cases  8.9 million new cases  1.6 million deaths, mostly in developing countries o differences in health care systems o poor living conditions & inadequate food supply o anything in contact w/ ill person were exposed to sun, open air for long periods of time b/c the sun helped o transmission – cough, sneeze, speak, kiss, or spit of ill person o most commonly attacks lungs o symptoms include chest pain, coughing up blood, & a productive, prolonged cough for more than three weeks, fever, chills, night sweats, appetite loss, weight loss, paleness & often a tendency to fatigue very easily – general health declines o old disease found in mummies in Egypt o used to run in families – transferred person to person o when pple used to marry it mattered if pple in the family had TB – 18 & 19 century o 18 – 20 century disease was related to vampires b/c sick poor pple were pale, had watery bloody eyes & coughed/spit blood & no one knew what caused the disease o Successful of antibiotics were found and most causes of TB were cured o TB agent mutates & these forms was resistant to antibiotics, making it difficult to cure o Not passed on genes but through bacteria o When come in contact w/ the bacteria the person may not show symptoms o TB is a problem in South Africa, South America, Asia 22  Anthrax o Bacillus anthracis (large gram-positive [used by microbiologists to for testing], spore-forming bacteria) o Spores of anthrax Normally found in soil, they live there o Spore is a form of bacteria, in a condition that doesn’t support the growth of the bacteria & survive o Produce toxins that are poisonous o Three major forms:  Cutaneous – through skin  The most common naturally occurring type [95% of pple]  After skin cont
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