1. INDUSTRIAL & ENVIRONMENTAL BIOTECHNOLOGY Course # KIBGE-707 AFSHEEN AMAN, Ph.D. Assistant Professor Industrial Biotechnology Section Dr. A.Q. Khan Institute of Biotechnology & Genetic Engineering (KIBGE) University of Karachi Pakistan 1

2. BIOAVAILABILITY & TOXICITY OF POLLUTANTS Course # KIBGE-707

3. ECOTOXICOLOGY The term ecotoxicology was coined by The term ecotoxicology was coined by in 1969 Rene Truhaut in 1969 Branch of toxicology concerned with the study of toxic effects, caused by natural or synthetic pollutants, to the constituents of ecosystems, animals (including human), vegetables and microbes” Branch of toxicology concerned with the study of toxic effects, caused by natural or synthetic pollutants, to the constituents of ecosystems, animals (including human), vegetables and microbes” Ecology in the presence of toxicants Ecology in the presence of toxicants 3

4. A 5-steps understanding process useful for research/regulation Release of pollutant into the environment Transport and fate into biota (with/out chemical transformation) Exposure to biological and ecological system Understanding responses and/or effects (molecular to ecological systems) Design experiments, remediation, minimization, conservation, and risk assessment plans to understand, eliminate, prevent or predict environmental and human health pollutions situations. 4

5. Ecotoxicity Subject of study of the field of ecotoxicology refers to the potential for biological, chemical or physical stressors to affect ecosystems. Such stressors might occur in the natural environment at densities, concentrations or levels high enough to disrupt the natural aspects that comprise the ecosystem. Biochemistry Physiology Behavior Interactions of the living organisms 5

6. Bioavailability of a pollutant The extent to which a pollutant is available to living things. Some compounds are very bioavailable to plants and animals because they are soluble in water; different compounds are soluble to different degrees. The extent to which a pollutant is available to living things. Some compounds are very bioavailable to plants and animals because they are soluble in water; different compounds are soluble to different degrees. If a substance is insoluble in water, or hydrophobic, it is generally not bioavailable. If a substance is insoluble in water, or hydrophobic, it is generally not bioavailable.

7. Hydrophobic compounds have an affinity for lipids and thus do not associate with water. Bioavailability will vary with soil structure and organic matter content. The higher the clay content of a soil, the more likely a pollutant is to be bound to the soil and therefore unavailable for plant uptake. 7

8. Clay soils have a smaller particle size, and thus more surface area. This high surface area provides for more exchange sites. Organic compounds that have a charge are subject to these exchange sites and become less bioavailable. High organic matter content in the soil will bind lipophilic (i.e. hydrophobic) compounds, making petroleum hydrocarbons less available. 8

9. TYPES OF POLLUTANTS Greenhouse Gases: Carbon dioxide and methane are two of the most important of these gases, called greenhouse gases because they trap heat in the earth's atmosphere. This is already causing severe problems around the world and the situation will only get worse. The rising temperatures will likely lead to more severe weather events, cause shifts in natural communities, and probably lead to greater species extinction rates, among numerous other effects.

10. Pesticides: A broad group of chemicals that enable us to live more comfortable lives by and large, but whose main purpose underlies the central problem with pesticide pollution. A lot of these chemicals will wash into our rivers and streams and cause direct toxicity to fishes, and may work their way up the food chain to affect birds, bears, whales, and other predatory wildlife, including humans.

11. Insecticides Fungicides Herbicides Plant-growth regulator Other compound They are all poisons 11

12.   Some of these pesticides will persist for long periods of time in the environment.   DDT was a pesticide used for along time in the US (and is still being used in parts of the world for mosquito control), but has been banned in the US since 1972.   Yet we still find DDT in our environment, sometimes at very high levels.

13. Heavy metals: Metals are continuously released into the biosphere by volcanoes, natural weathering of rocks but also by numerous anthropogenic acitivities, such as mining, combustion of fuels, industrial and urban sewage and agricultural practices. Metals are continuously released into the biosphere by volcanoes, natural weathering of rocks but also by numerous anthropogenic acitivities, such as mining, combustion of fuels, industrial and urban sewage and agricultural practices. On a global scale there is now abundant evidence that anthropogenic activities have polluted the environment with heavy metals from the poles to the tropics and from the mountains to the depths of the oceans. On a global scale there is now abundant evidence that anthropogenic activities have polluted the environment with heavy metals from the poles to the tropics and from the mountains to the depths of the oceans. 13

14. Most heavy metals, such as mercury, are a natural part of the earth's crust, and would be slowly released into the environment over time just by weathering of soils and rocks. However, our consumption of fossil fuels has greatly increased the introduction of heavy metals into our environment. 14

15. The world-wide emissions of metals to the atmosphere by natural sources is estimated as (thousand t yr-1): Ni: 26, Pb: 19, Cu: 19, As: 7.8, Zn: 4, Cd: 1.0, Se: 0.4 Whereas, from anthropogenic sources (thousand t yr-1): Pb: 450, Zn: 320, Ni: 47, Cu: 56, As: 24, Cd: 7.5, Se: 1.1 15

16. It is estimated that half of the mercury introduced into the environment today is due to human sources. The problem is mercury, as well as other heavy metals, that cannot be detoxified. Once it is in the environment, it is here for good. Toxic effects of heavy metals vary. 16

17. Mercury is a potent toxin in people targeting nervous tissue, but targets other tissues in other animals. The effects of heavy metals can also be quite severe, since plants and animals have no natural ability to deal with heavy metals specifically and heavy metals do not have any functions in our bodies.

18. List of Environmental Issues Climate change — Global warming Fossil fuels Sea level rise Greenhouse gas Ocean acidification Conservation — Species extinction Pollinator decline Coral bleaching Holocene extinction event Invasive species Endangered species Dams — Environmental impacts of dams Energy — Energy conservation Renewable energy Efficient energy use Renewable energy commercialization Intensive farming — Overgrazing Irrigation Monoculture Environmental effects of meat production

19. Land degradation — Land pollution Desertification Soil — Soil conservation Soil erosion Soil contamination Soil salination Land use — Urban sprawl Habitat fragmentation Habitat destruction Nanotechnology — Nanotoxicology Nanopollution Nuclear issues — Nuclear fallout Nuclear meltdown Nuclear power Radioactive waste Overpopulation — Burial Ozone depletion — CFC

20. ichlorodiphenyltrichloroethane) Toxins — Chlorofluorocarbons DDT (dichlorodiphenyltrichloroethane) Endocrine disruptors Dioxin Heavy metals Herbicides Pesticides Toxic waste Bioaccumulation Waste — E-waste Litter Waste disposal incidents Marine debris Landfill Recycling Incineration Genetic engineering — Genetic pollution Genetically modified food controversies

21. THANK YOU 21