Transcript D.6 Environmental Impact of Some Medicines

Environmental Impact of
Some Medications
Medical Waste and the Environment
 For many years, the environmental impact of medical waste has been
ignored as scientists concentrated on well known contaminants
generated by the agricultural and industrial sectors.
 Pharmacologically active compounds (PACs) used in medicine and in
biochemical studies have not been treated as potentially toxic and
have been routinely released to the environment.
 Prolonged exposure to PACs causes significant changes in the
metabolism and behavior of various organisms.
Medical Waste and the Environment
 1) The uncontrolled release of antibiotics to the environment leads to the
development of resistant bacteria, while other drugs can act as endocrine disruptors,
increasing the risk of cancer and reproductive disorders in humans and other animals.
 2) Radioactive materials used in medical treatment and diagnostics is another type
of environmental pollutant. It can increase radiation levels in local ecosystems
because it was often disposed of as common waste.
 3) Organic solvents used in the pharmaceutical industry contribute significantly to
chemical waste. Most solvents are toxic to living organisms, primarily affecting the
nervous and respiratory systems, the liver, the kidney, and the reproductive organs.
Antibiotic Resistance
 The widespread use of penicillin and other antibiotics in the second half of the 20th
century lead to the development of antibiotic resistance in many strains of harmful
bacteria. For example, extensive use of broad-spectrum antibiotics, those used
against a wide range of bacteria, has enabled infections such as Clostridium Difficiile
to thrive.
 Consequently, the efficiency of traditional antibiotics against common diseases has
decreased significantly.
 Scientists need to create new drugs in order to combat bacterial infections, however,
it becomes progressively more difficult as bacteria constantly become resistant to
increasing numbers of antibiotics.
Antibiotic Resistance
Uses of Antibiotics
 Less than half of antibiotics produced are used for treatment of disease in
humans. Others include:
http://www.forbes.com/sites/brucelee/2017/01/15/w
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 There are no simple solutions to the problem of antibiotic-resistant bacteria.
But, it is obvious that antibiotic therapy should be restricted to the most
severe cases of bacterial infections while non-medical use of antibacterial
drugs should be banned completely.
 At the same time, the amount of antibiotic waste from hospitals and the
pharmaceutical industry must be reduced to a minimum and thoroughly
processed before being released into the environment.
 Additionally, individuals can contribute to the solution by avoiding overuse,
and by complying with instructions to complete a prescribed dose.
 Finally, to be effective, these measures need to be taken by all countries
and coordinated at the international level.
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 in water-soluble salts or
radiopharmaceutical drugs, while others are used in medical equipment as
sources of ionizing radiation.
 During medical procedures radionuclides and ionizing radiation come into
contact with various materials that also become radioactive. These
materials together with left-over radionuclides, produce nuclear waste,
which must be disposed of in accordance with specific procedures.
Nuclear Waste
 High-level waste gives off large amounts of ionizing radiation for a long time. The
isotopes have long half-lives.
 HLW is produced in nuclear reactors. Many radionuclides in HLW have very long
half-lives, from decades to billions of years. Spent isotopes from medical diagnosis
techniques may also generate some high level waste, although this amount is quite
small relative to the amount of high level waste generated by the nuclear energy
industry.
 The treatment, transportation, and disposal of nuclear waste present serious risks
due to possible release of radionuclides to the environment, which is very harmful to
all living organisms because it causes extensive cellular and genetic damage.
Nuclear Waste
Organic Solvents
Organic Solvents
Organic Solvents
Green Chemistry
 The primary goal of green chemistry is to reduce the environmental impact
of technological processes by minimizing the use and generation of
hazardous chemicals
 This branch of chemistry focuses on 12 principles. These principles cover
concepts such as avoiding wastes, maximizing the amount of raw material
that ends up in the product, and the use of safe solvents.
 Common practices of green chemistry include aqueous or solvent free
reactions, renewable starting materials, mild reaction conditions, and the
utilization of any by-products formed during the synthesis.