Connecting Global Priorities Biodiversity and Human Health

several potential knock-in impacts on human wellbeing,
including increased public health risks.
Although numerous detailed risk assessments
suggest that environmental concentrations of
most APIs in isolation are unlikely to have any
significant impact on biodiversity, these examples
illustrate that there is reason for concern; there
is a need for more integrated environmental
risk assessments that account for ecological
interactions, and more effort is needed to
understand the risks associated with mixtures of
APIs in the environment (Backhaus 2014).
Another issue of concern related to both human
and veterinary APIs in the environment, with
more widespread implications for human health,
is the link to the growing threat of antimicrobial
resistance. The number and diversity of drugresistant
pathogens is increasing, and a slowdown
in the production of new antimicrobial drugs since
the 1980s means that existing treatments are
increasingly ineffective against several important
human diseases (WHO 2014). Research has shown
that drug-resistant infections accounted for a large
number of emerging infectious diseases in the
past 30 years, and that multidrug resistance (when
an infection shows resistance to a range of drugs
normally used to treat it) is a serious and growing
concern (Jones 2008; Levy and Marshall 2004).
The causes of antimicrobial resistance are complex,
and although genes for antibiotic resistance occur
widely in nature without human influence, the
inappropriate use and overuse of antimicrobials,
including the non-therapeutic use of antibiotics
as growth promoters in agriculture, is a major
cause of drug resistance (WHO 2012). The risk
of resistance is also increased by the routine
disposal of drugs and drug residues. The release
of antimicrobial drugs into the environment
from human use and manufacturing, veterinary
applications, disposal at landfill sites, or use in
aquaculture increases the exposure of microbes to
those drugs, and thereby increases the potential
for the development of drug resistance. Research
has shown that pollution and patterns of human
water use are important risk factors (Pruden et
al. 2012, 2013; Wellington et al. 2013), and that
drug-resistant microbes are found in nature and
can be carried by wildlife, particularly by animals
associated with agriculture or human settlements
(Radimersky et al. 2010; Taylor et al. 2011; Carroll
et al. 2015), and persist in agricultural soils
(Kyselková et al. 2015).
social and environmental changes
The range of factors affecting the occurrence
of APIs in the environment is by now well
understood. The science of risk assessment for
these pollutants is also increasingly advanced,
with product risk assessment based on product
usage (or estimated usage for novel drug entities),
estimates of wastage, (bio)degradation studies,
and assessment of ecological toxicity. However, a
number of important issues surrounding inputs to
the environment remain to be addressed.
For example, changing demographics are likely to
significantly alter the type, range and quantities of
APIs being utilized at the local and regional levels.
For human APIs, ageing populations, increased
migration, economic transitions in developing
countries, and urbanization are all likely to
see shifts in the use profiles of pharmaceutical
products. Changes in agricultural practice –
to accommodate the increased demand for
specific foods, including responses to nutrition
transitions and conversion of natural habitats
for food production – are likely to see changes
in the quantities and kinds of animal health
products in use. Climate change is also expected
to have an impact by affecting the ecology of
various pathogens in humans, domestic animals
and wildlife, and thereby potentially leading to
demands for the increased use of certain drugs,
and development of new drug entities to address
increased or emerging health threats. Climate
change may also affect how APIs occur in the
environment and their relative risks to biodiversity.
For example, changes in surface water run-off,
changing water and soil temperatures, and changes
in natural vegetation and wildlife populations
may be expected to affect the movement and
degradation of APIs in the environment, their
bioavailability, and the types of species exposed to
different API compounds. Therefore, further work
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