Environmental Engineering Reference
In-Depth Information
- Some react with DNA and cause structural changes that lead to miscopying of the
template strand when the DNA is replicated;
- Some work indirectly by causing the cells to synthesize chemicals that have the
direct mutagenic effect.
Some typical mutagenic agents and chemical substances:
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Ionizing radiation, for example, X-rays, gamma rays and alpha particles;
-
Ultraviolet, electromagnetic radiation with a wavelength shorter than that of
visible light but longer than X-rays;
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Base analog, which can substitute for DNA bases and cause copying errors;
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De-aminating agents such as nitrous acid;
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Intercalating agents such as ethidium bromide;
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Alkylating agents such as ethylnitrosourea;
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Bromine and some compounds that contain bromine in their chemical structure;
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Sodium azide, a common reagent in organic synthesis and a component in many
car airbag systems;
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Benzene, an industrial solvent and precursor in the production of drugs, plastics,
synthetic rubber and dyes;
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PAHs, contaminants of the atmosphere, cooked and grilled food as well
as toast. The most toxic 17 deserve special attention: acenaphthene, ace-
naphthylene, anthracene, benz[a]anthracene, benzo[a]pyrene, benzo[e]pyrene,
benzo[b]fluoranthene, benzo[ghi]perylene, benzo[j]fluoranthene, benzo[k]
fluoranthene, chrysene, coronene, dibenz[a,h]anthracene, fluoranthene, fluorine,
indeno(1,2,3-cd)pyrene, phenanthrene, pyrene;
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Natural mutagens, such as pyrrolizidine alkaloids, cyasin or mycotoxins of fungi;
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Psoralen, the parent compound of furocoumarins occurring in seeds and plants.
Combined with ultraviolet radiation it causes DNA cross-linking and hence
chromosome breakage.
8 REPROTOXIC SUBSTANCES
Reprotoxic is a chemical substance which may cause reproductive toxicity. Reproduc-
tive toxicity includes adverse effects on sexual function and fertility in adult males and
females, adverse effects on gonads and disturbance of spermatogenesis, as well as devel-
opmental toxicity in the offspring. Reprotoxic chemicals can damage the reproductive
process by the following:
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Adverse effects on sexual function and fertility;
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Adverse effects on development;
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Effects on or via lactation.
Chemicals with diverse adverse effects may result in the above listed negative
impacts on reproductivity: toxic effects on the gametes, the embryo, the fetus or
the newborn child, endocrine disrupting agents influencing gamete maturation and
conceiving, mutagens changing the genome of the gametes or the early embryos, devel-
opmental toxicants (teratogenic chemicals) adversely affecting the development of the
fetus, etc.
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