27.6.8 Micropollutants, Emerging Contaminants, Currently
Used Pesticides
Over the last decades, the occurrence of micropollutants in the environment has
become a worldwide issue. Micropollutants, also termed contaminants of emerging
concern, include both anthropogenic as well as natural substances such as pharmaceuticals, personal care products, steroid hormones, industrial chemicals, pesticides,
and many others. Micropollutants are commonly present in the environment at trace
concentrations that may range from few ng/L to several μg/L (Luo et al. 2014; Loos
et al. 2010, 2013). Complex description of the ecotoxicology of these diverse
compounds is beyond the scope of the present chapter; therefore, we discuss only
the most prominent and well-documented examples.
Brominated flame retardants (BFRs) are polybrominated compounds broadly
used as additives—flame retardants—to materials and products like plastics, textile,
furniture, electronics, etc. The most important representatives are polybrominated
diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD), tetrabromobisphenol
A (TBBPA), or polybrominated biphenyls (PBBs). They are ubiquitous contaminants with high hydrophobicity, stability, bioaccumulative potential, and toxicity.
The main documented effects are—similarly to many POPs—related to chronic
exposures of larger animals and include reproduction toxicity, disruption of development and growth, immunotoxicity, or other endocrine-disruptive effects. Because
of their hazardous properties, some of the mentioned classes like PBDEs or HBCD
have recently been added to the list of UNEP Stockholm Convention.
Pharmaceuticals and personal care products (PPCPs) have become of great
research concern, especially with respect to their potential chronic toxic effects that
are not usually captured in standardized acute toxicity effects (Ortiz de García et al.
2014). The most extensively studied examples include estradiol and 17-alphaethinylestradiol known to cause reproductive disruptions in fish at very low ng/L
concentrations. Other highly potent fish endocrine and reproductive disrupters are
trenbolone (androgen) or levonogestrel. Some broadly used non-steroidal antiinflammatory drugs (pain killers) like diclofenac or ibuprofen are also known to
cause kidney and liver toxicity or affect spawning in fish at low concentrations
(LOEC <1 μg/L). Other examples include, e.g., transgenerational effects of antibiotics in D. magna (Dalla Bona et al. 2015) or ecotoxicity and genotoxicity of anticancer drugs (Isidori et al. 2016; Zounková et al. 2011).
Although legacy pesticides like DDT and other OCPs have been mostly banned,
they are being replaced with currently used pesticides (CUPs) to assure necessary
agriculture production. CUPs are used annually in large amounts and a majority
enters the soil forming thus short- or long-term residues. Acute ecotoxicity of CUPs
is considered low as strict procedures and risk assessment is required before their
authorization. However, chronic toxicity to non-target species is of concern as recent
27 Ecotoxicology of Environmental Pollutants
567
Used Pesticides
Over the last decades, the occurrence of micropollutants in the environment has
become a worldwide issue. Micropollutants, also termed contaminants of emerging
concern, include both anthropogenic as well as natural substances such as pharmaceuticals, personal care products, steroid hormones, industrial chemicals, pesticides,
and many others. Micropollutants are commonly present in the environment at trace
concentrations that may range from few ng/L to several μg/L (Luo et al. 2014; Loos
et al. 2010, 2013). Complex description of the ecotoxicology of these diverse
compounds is beyond the scope of the present chapter; therefore, we discuss only
the most prominent and well-documented examples.
Brominated flame retardants (BFRs) are polybrominated compounds broadly
used as additives—flame retardants—to materials and products like plastics, textile,
furniture, electronics, etc. The most important representatives are polybrominated
diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD), tetrabromobisphenol
A (TBBPA), or polybrominated biphenyls (PBBs). They are ubiquitous contaminants with high hydrophobicity, stability, bioaccumulative potential, and toxicity.
The main documented effects are—similarly to many POPs—related to chronic
exposures of larger animals and include reproduction toxicity, disruption of development and growth, immunotoxicity, or other endocrine-disruptive effects. Because
of their hazardous properties, some of the mentioned classes like PBDEs or HBCD
have recently been added to the list of UNEP Stockholm Convention.
Pharmaceuticals and personal care products (PPCPs) have become of great
research concern, especially with respect to their potential chronic toxic effects that
are not usually captured in standardized acute toxicity effects (Ortiz de García et al.
2014). The most extensively studied examples include estradiol and 17-alphaethinylestradiol known to cause reproductive disruptions in fish at very low ng/L
concentrations. Other highly potent fish endocrine and reproductive disrupters are
trenbolone (androgen) or levonogestrel. Some broadly used non-steroidal antiinflammatory drugs (pain killers) like diclofenac or ibuprofen are also known to
cause kidney and liver toxicity or affect spawning in fish at low concentrations
(LOEC <1 μg/L). Other examples include, e.g., transgenerational effects of antibiotics in D. magna (Dalla Bona et al. 2015) or ecotoxicity and genotoxicity of anticancer drugs (Isidori et al. 2016; Zounková et al. 2011).
Although legacy pesticides like DDT and other OCPs have been mostly banned,
they are being replaced with currently used pesticides (CUPs) to assure necessary
agriculture production. CUPs are used annually in large amounts and a majority
enters the soil forming thus short- or long-term residues. Acute ecotoxicity of CUPs
is considered low as strict procedures and risk assessment is required before their
authorization. However, chronic toxicity to non-target species is of concern as recent
27 Ecotoxicology of Environmental Pollutants
567