1. OPTION D – Medicinal Chemistry
D.6 – Environmental Impact of Some Medications
Apr 21, 2017

2. Medical Waste
Medical waste has now become a real and significant environmental problem.
Improper disposal of pharmacologically active compounds (PACs) has contributed to drug-resistant strains of bacteria. Prolonged exposure to PACs causes significant changes in the metabolism of various organisms.
Radioactive materials used for medical treatment and diagnostics are also significant environmental pollutants. While their activity is low, their disposal and normal waste is adding to the radiation levels of local ecosystems.

3. Antibiotic Resistance
The widespread use of penicillin and other antibiotics have led to the development of antibiotic resistance among many harmful strains of bacteria.

4. Antibiotic Resistance
Antibiotic resistance creates some real problems for the maintenance of human health.
Efficiency of traditional antibiotics on common illnesses has been greatly reduced; which requires the continuous development of new and stronger antibiotics.
Antibiotic resistance is caused by a number of factors:
1. Over-prescription of antibacterial medications
2. Non-compliance of patients in finishing a course of treatment
3. Use of antibiotics in agriculture

5. Impact of Antibiotic Resistance
Decades of using antibiotics to prevent disease in animals have reduced animals’ natural immunity to bacteria. This has made the animals more susceptible to infection and has resulted in the increased death rate of agricultural animals.
Evidence points to similar reduction of natural immunity in the human population as well.
As a result, there is a move toward restricting the use of antibiotics to treatment of only the most severe bacterial infections, and the ban of their use in agriculture and other non-medical industries.
Jan 3, 2010

6. Nuclear Waste
Many medical procedures involve the use of radionuclides – unstable isotopes of certain elements that undergo spontaneous radioactive decay.
Some of these isotopes are administered to patients as water-soluble salts , while other radionuclides are used in medical equipment as sources of ionizing radiation. These radionuclides, together with various materials they come in contact with become nuclear waste.
Thiis nuclear wastes fall into 2 categories; Low-Level Waste (LLW) and High-Level Waste (HLW), and must be disposed of in accordance with special procedures.

7. Nuclear Waste
Low-Level Waste (LLW) are most of the radionuclides with low activity and short half-lives that are used in hospitals and medical research centers. These include syringes, tools, swabs, paper, and protective clothing. Such waste has limited environmental impact and is usually suitable for shallow landfill or incineration.
Some types of LLW, such as concentrated solutions of radionuclides, must be stored for seveal days or weeks in shielded containers until most of the radioactive isotopes have decayed and the radiation level has dropped below a safe limit.

8. Nuclear Waste
High-Level Waste (HLW) are radionuclides that remain active for many years and produce very high levels of ionizing radiation. These include wastes from nuclear reactors that contain nuclear fission products with unused nuclear fuel.
Due to ongoing nuclear reactions, concentrated HLW releases heat and must be constantly cooled with water for up to several years. When the radioactivity level decreases, HLW can pe vitrified (fused with glass) or immobilized in certain minerals “Synroc” or “synthetic rock” that is water-resistant and chemically stable solid.
Jan 3, 2010

9. Nuclear Waste
Treatment, transportation, and disposal of nuclear waste present serious risks due to possible release of radionuclides to the environment.
High doses of ionizing radiation are harmful to all living organisms, causing
cell damage
genetic mutations
cancer
birth defects
reproductive disorders.
weakened immune system
The effects of ionizing radiation can be cumulative as an environmental pollutant.

10. Pharmaceutical Wastes
Many pharmaceutical drugs are produced on an industrial scale. Most of these processes involve the use of toxic chemicals that have to be recycled or disposed of after the synthesis is complete. They include:
Organic solvents
Clorinated solvents
Jan 3, 2010

11. Green Chemistry
While the measure of efficiency in traditional is measured in terms of product yield and cost of materials.
The primary goal of green chemistry, by contrast, is to minimize the environmental impace by minimizing the use and generation of hazardous chemicals. Some common practices include:
aqueous or solvent-free reactions
renewable starting materials
mild reaction conditions,
regio- and steroselective catalysis, and
utilization of any by-products formed during the sysnthesis

12. Green Chemistry
Atom economy expresses the efficiency of a synthetic procedure as the ratio between the molecular mass of the isolated target product and the combined molecular masses of all starting materials, catalysts, and solvents used in the reaction.
An intermediate, shikimic acid, which has been extracted from star of anise for many years, is a precursor to the antiviral drug oseltamivir (Tamiflu). This intermediate can be produced from renewable materials.
The adoption of green technological processes in developed countries has significantly reduced the emissions of many hazardous chemicals shuch as chlorinated solvents and greenhouse gases.

13. Homework Answer question at the end of the section (pg. 757).
Complete Kerboodle quizzes.
Study for TEST.