1.27k likes | 2.34k Views
Bio-Akumulasi. KAJIAN EKOTOKSIKOLOGI. Paparan, perilaku, dan transport Bio-akumulasi Toksisitas Bioakumulasi: uptake - ekskresi. The Wildlife Research Strategy at the intersection of the disciplines of ecotoxicology, population biology, and landscape ecology.
E N D
KAJIAN EKOTOKSIKOLOGI • Paparan, perilaku, dan transport • Bio-akumulasi • Toksisitas • Bioakumulasi: uptake - ekskresi The Wildlife Research Strategy at the intersection of the disciplines of ecotoxicology, population biology, and landscape ecology. Diunduh dari: http://www.ecologyandsociety.org/vol11/iss1/art23/figure1.html
Bioakumulasi • Akumulasi dari semua sumber • Air, Udara. Padatan • Biokonsentrasi: hanya dari air Lake Ontario Biomagnification of PCBs Bioaccumulation is the sum of two processes: bioconcentration and biomagnification. Read more: Bioaccumulation - water, environmental, pollutants, EPA, chemicals, toxic, lifehttp://www.pollutionissues.com/A-Bo/Bioaccumulation.html#ixzz3npXNLAgG
Kajian bioakumulasi? • Minamata Bay, Japan. 1956. Hg pollution. Landmark for environmental studies. • DDT pesticides. egg shell thinning • TBT, oyster shell thickness, imposex in snails • Tanpa lingkungan yang baik, kita tidak dapat bertahan hidup!
Bioakumulasi vs. Toksisitas • Linking the two is challenging • Predicting them is also difficult Bioaccumulation Toxicity Prediction???
Istilah Bioakumulasi Bioaccumulation of Mercury When mercury falls in rain or snow, or when it falls out of the air as dry deposition, it may eventually be washed into waterbodies by rain. • Bioavailability: fraction available • Bioconcentration: uptake from water • Bioaccumulation: uptake from water and food Methylmercury accumulates as you move up the food chain: Methylmercury in the water and sediment is taken up by tiny animals and plants known as plankton. Small fishes eat large quantities of plankton over time. Large predatory fish consume many smaller fish, accumulating methylmercury in their tissues. The older and larger the fish, the greater the potential for high mercury levels in their bodies. Diunduhdari: http://www.mercury.utah.gov/bioaccumulation.htm
Istilah Bioakumulasi • Biomagnification: increase in conc at higher levels • Body burden, concentration • Equilibrium: between compartments • Steady-state: within one compartment, in and out equal
Istilah dalam bioakumulasi • Koefisien Partisi (Kd) / Kow • Laju Eliminasi • Laju Depuration • Asimilasi • Absorption / Penyerapan • Adsorption / Penjerapan • Toxicokinetics
Jalur-jalur Paparan Bahan Kimia • Water • Food • Sediments • Bioaccumulation: uptake - excretion Diunduh dari : http://www.atsdr.cdc.gov/sites/springvalley/images/exposure_pathways.gif
Uptake senyawa / bahan kimia • Lipophilic: lipid biolayer, untuk molekul polar yang tidak bermuatan • Aqueous: difasilitasi, aktif • Endositosis: untuk nanopartikel dan makro-molekul Basic Mechanism of Phytoextraction of Heavy Metals http://bio349.biota.utoronto.ca/20079/20079bio349sasha/phytoextraction.html
Transport senyawa Kimia • Proses difusi pasif: • Dari konsentrasi tinggi menuju ke konsentrasi yang lebih rendah • Tidak memerlukan ligand • Transport yang difasilitasi: • Dari konsentrasi tinggi ke konsentrasi yang lebih rendah • Memerlukan Ligand
Transport senyawa Kimia Source Identification of Florida Bay's Methylmercury Problem: Mainland Runoff versus Atmospheric Deposition and In Situ Production. By Darren Rumbold1, Larry Fink1, Nicole Niemeyer1, Angela Drummond1, David Evans2, David Krabbenhoft3, and Mark Olson31South Florida Water Management District, West Palm Beach, Fl., USA2National Oceanic and Atmospheric Administration, Beaufort, NC., USA3US Geological Survey, Middleton, WI., USA THg and MeHg in sediments collected semi-annually from the bay and upstream canals ranged from 5.8 to 145.6 ng/g dry weight (median was 19.9 ng THg/g) and from 0.05 to 5.4 ng/g dry weight (median was 0.26 ng MeHg/g), respectively. Although the highest median THg concentration occurred in sediment from the C111 Canal (115 ng/g), sediments from the mangrove transition zone along both flowpaths also contained relatively high levels of THg. The highest median sediment-MeHg (1.76 ng/g) occurred at the mouth of Taylor River. While these data must be normalized based on total organic carbon (measured in later cores) before any definitive conclusions can be reached, it was clear that sediments both from upstream marshes and from the bay often contained elevated concentrations of MeHg. Sediments collected from near Nest Key, for example, contained up to 1.8 ng MeHg/g, which constituted almost 8 percent of the THg present. • Transport Aktif • Dari konsentrasi rendah ke konsentrasi tinggi • Diperlukan energi • Adsorption /Penjerapan: Fisiko-kimia
Adsorption / Penjerapan • Model penjerapan menurut Freundlich : Model Empirik • X/M = kC1/n X adalah jumlah yang dijerap, M adalah masa penjerap (adsorbent), k adalah konstante, C adalah konsentrasi “solute” setelah proses penjerapan
Adsorption/ Penjerapan Dose-dependent growth inhibition and bioaccumulation of hexavalent chromium in land snail Helix aspersa aspersa by Michael Coeurdassier, Annette Gomot-de Vaufleury, Pierre-Marie Badot Environmental Toxicology Chemistry (2000) Volume: 19, Issue: 10, Pages: 2571-2578 The toxicity of Cr6+ was determined in a laboratory environment in the snail Helix aspersa aspersa. The effects on growth were evaluated on animals reared in controlled conditions at the age of one month that had been exposed for 28 d to increasing doses of Cr6+ mixed in with their food. Two experimental groups were set up with concentrations of chromium in the feed of 250 to 1,250 Mu g/g(test 1) and 100 to 800 Mu g/g (test 2). Growth inhibition was dose dependent, and the mean EC50 calculated at four weeks for tests 1 and2 were, respectively, 354.7 and 298.8 Mu g/g and for the EC10 195.3 and 160.9 Mu g/g. The levels of Cr6+ bioaccumulated in thefoot and the viscera of the snails were dose dependent in both typesof tissues. The highest concentrations occurred in the viscera, the levels being 0.79 Mu g/g in the controls and reaching 3,067 Mu g/g inthe animals exposed to the maximum contamination (1,250 Mu g/g). These high levels of bioaccumulation in addition to the lower concentrations of Cr6+ excreted in the feces than those present in the food suggest that chromium is not physiologically regulated by Helix aspersa. The results provide added support for the use of snails as a model to determine the toxicity of substances in laboratory biotests by measuring the effects on growth and by assessing bioaccumulation. • Model Penjerapan Langmuir : Model Teoritis • X/M = abC/(1+bC) “a” adalah jerapan maksimum “b” adalah afinitas regresi linear
Difusi • Pergerakan suatu material kimia menuruni gradien elektron • Difusi sederhana: Saluran ion, Lapisan lemak • Difusi difasilitasi: Memerlukan carrier. • Difusi pertukaran – Pertukaran ion.
Diffusion • Proses difusi dapat dijelaskan dengan Hukum Fick: • dS/dt = -DA dC/dx • S is the movement across the surface, D is the diffusion coefficient, A is the surface area • dC/dx is the concentration gradient across the boundary of interest.
Transport Aktif • Melawan gradien kimiawi elektron • Memerlukan energi seperti ATPase, pompa ion • Beberapa jenis logam dapat diangkut dengan transport aktif • Cd-Ca • Cs-K
Endocytosis • Pinocytosis • Phagocytosis • Fe-transferrin protein. Metalloproteins and metalloenzymes These are metal complexes of proteins. In many cases, the metal ion is coordinated directly to functional groups on amino acid residues. In some cases, the protein contains a bound metallo-cofactor such as heme. In metalloproteins with more than one metal-binding site, the metal ions may be found in clusters. Examples include ferredoxins), and nitrogenase, which contains both Fe4S4 units and a novel MoFe7S8 cluster. Read more: http://www.answers.com/topic/bioinorganic-chemistry#ixzz3nk96spoz Iron complex of protoporphyrin IX, or heme.
Biotransformation/detoxification The Liver Detoxification Pathways Inside the liver cells there are sophisticated mechanisms that have evolved over millions of years to break down toxic substances. Every drug, artificial chemical, pesticide and hormone is broken down (metabolised) by enzyme pathways inside the liver cells. Many of the toxic chemicals that enter the body are fat-soluble which means they dissolve only in fatty or oily solutions and not in water. Fat-soluble chemicals have a high affinity for fat tissues and cell membranes, which are made of fatty substances. In these fatty parts of the body toxins may be stored for years, being released during times of exercise, stress or fasting. During the release of these toxins, symptoms such as headaches, poor memory, stomach pain, nausea, fatigue, dizziness and palpitations may occur. The liver is designed to convert fat-soluble chemicals into water-soluble chemicals so that they may then be easily excreted from the body via watery fluids such as the bile and urine. Sumber: http://www.positivehealth.com/article/weight-loss/a-healthy-liver-and-weight-loss • Biotransformation: biologically mediated such as enzymes • Elimination • Detoxification • Sequestration • Redistribution • Activation
Transformasi Logam • Bio-methylation, Methyl-Hg, bio-transformasi • Metallothionein,<7000 Da. 25-30% amino acid as cysteine. • Phytochelatins (in plants): glutothioneine / cysteine • Bio-mineralisasi / sequestration
Senyawa Organik • Phase I reaction: add –COOH, -OH, -NH2, -SH to increase hydrophilicity (add O by MFOs) • Phase II: form conjugates (glucuronic acid, etc) to inactivate and foster elimination.
Elimination • Elimination: metabolism/excretion • Depuration: untuk mencuci lingkungan • Clearance: untuk kontaminan organik • Growth dilution • Efflux • There are subtle differences among these terms
Mekanisme Eliminasi Urine is produced in the glomeruli and renal tubules and carried to the renal pelvis by collecting tubules. The glomeruli act as simple filters, through which water, salts, and waste products from the blood pass into the spaces of Bowman's capsules and from there down into the renal tubules. Most of the water and salt is reabsorbed from these tubules; the remainder is excreted as urine. The renal tubules also secrete other salts and waste products from the blood into the urine. The average amount of urine excreted in 24 hours is about 1.4 litres (2.4 pt), but the quantity varies considerably, depending on intake of fluid and loss from such sources as the skin in perspiration, or from vomiting. Diunduh dari: http://dspace.dial.pipex.com/town/plaza/jc75/inf_2.htm • Ekskresi (melalui ginjal) • Molting • Produksi telur • Hilang dalam bentuk bulu/rambut, kulit, insang • Exhalation
Pemodelan Eliminasi • Model berbasis laju-konstan • Sederhana , fungsi kehilangan orde pertama • dC/dt = -kC • Ct = Co*exp(-kt) t1/2 adalah waktu paruh biologis (retention life) = ln2/k
Pemodelan Eliminasi Fungsi kehilangan dua kompartemen: • Ct = C1*exp(-k1t) + C2*exp(-k2t) Back stripping technique (C2 first, then C1)
Pemodelan Eliminasi • Model yang lebih rumit: • dC1/dt = k21XC2-(k10+k12)xC1 • dC2/dt = k12xC1 – k21xC2
Kontrol Akumulasi • Kualitas Senyawa/Bahan Kimia • Species • Bentuk senyawa kimia • Biologis • Physiologis dan biokimia • Genetik • Ecologis • Perilaku • Kondisi Lingkungan • Temperatur, Salinitas • pH, Unsur Hara
Ketersediaan Biologis • Bebas untuk penyerapan • Bebas untuk diambil dan menyebabkan efek pada tempat berlangsungnya proses
Kualitas Kimia-Logam : Air • Spesies-spesies Ion bebas • Free ion + inorganic complex ion + organic complex ion • Free ion is the most important species bioavailable to the organisms and causing toxicity (the so called free ion activity model—FIAM)
Ion dan Spesiasinya dalam Air laut • Anion: Cl, HCO3, CO3, F, PO4, NH3, SO4, SiO4, OH • Kation: H, K, Na, Ca, Mg • Logam: • Cd: CdCl2 • Ag: AgCl2- • Zn: Zn2+, ZnOH+, ZnCO3, ZnCl+
Model FIAM • Implikasi dari Model • Contoh-contoh • Perkecualian : HgCl2, AgCl • Mekanisme transport logam Metal Uptake by Phytoplankton. (Adapted from Kustka et al, Journal of Phycology, 2007) Diunduh dari: http://www.princeton.edu/morel/research/metal-uptake/
FIAM Journal of Environmental Science and Management, Vol 14, No 2 (2011) Bioaccumulation in Nile Tilapia (Oreochromis niloticus) from Laguna de Bay, Philippines Victorio B. Molina, Ma. Victoria O. Espaldon, Maxima E. Flavier, Enrique P. Pacardo, Carmelita M. Rebancos This study provides an assessment of the risks to human health associated with the exposure to heavy metals bioaccumulation in Nile tilapia (Oreochromis niloticus) from Laguna de Bay. Samples of the fish were collected in eight sampling stations in three major areas of the lake during the dry and wet seasons. Dry season samples were collected from May to June 2010 and wet season samples from September to November 2010. Coordinates of sampling site locations were recorded using Global Positioning System (GPS) and plotted in Geographic Information System (GIS) digital maps. Heavy metals analyses for cadmium (Cd), lead (Pb), mercury (Hg), arsenic (As), and chromium (Cr) were conducted using am Atomic Absorption Spectrophotometer (AAS) and a Mercury Analyzer (Mercur-Duo). Estimates of health risks associated with fish consumption were summarized according to non-carcinogenic and carcinogenic health effects. Non-carcinogenic Health Quotient (NHQ) values of the five heavy metals showed that lead is the most urgent pollutant of concern in terms of adverse health effects from risks associated with fish consumption from all sampling locations in the lake. Among the five heavy metals only arsenic is a confirmed human carcinogen (Class A) through the oral route of exposure. The highest life time cancer risk for arsenic was computed from sampling station 2B (west bay) during the dry season with risk value of 8.5x10-4 or an excess of 85 cancer cases per 100,000 population. From the point of view of human health protection and disease prevention, the Nile tilapia from Laguna de Bay is not fit for human consumption due to arsenic and lead contamination. Campbell dan Tessier (1996): Aktivitas logam-bebas sangat menentukan serapan, nutrisi dan toksisitas semua kation logam-logam mikro
KONTAMINAN ORGANIK • Kow secara langsung mempengaruhi akumulasi kontaminan organik dalam organisme akuatik. • QSAR: Quantitative Structural Activity Relationship. • BCF: Faktor Biokonsentrasi