TCoPS - 20

BEYOND THE COSTS THAT ARE CURRENTLY
QUANTIFIABLE, THERE ARE ADDITIONAL NEGATIVE
CONSEQUENCES OF PLASTIC PRODUCTION,
CONSUMPTION AND DISPOSAL THAT ARE NOT YET
FULLY UNDERSTOOD.
The currently quantifiable lifecycle cost of plastic
is significant, but this could be just the tip of the
iceberg. Data and research gaps and limitations in
estimation techniques restrict the quantification of all of the
negative impacts of plastic. Therefore, there are many known
unknowns associated with the plastic lifecycle. This section
focuses on a limited subset to outline the problem.
The production, incineration, and open burning of
plastic polymers releases chemical pollutants that
pose a significant threat to human health.
Plastic production processes release chemical
pollutants, putting populations at risk of negative
health impacts. The extraction of oil and gas for plastic
production releases countless toxic substances into the
air and water, often in significant volumes.113
Over 170
fracking chemicals used to produce the main feedstocks
for plastic are known to cause human health problems,
including cancer and neurotoxicity.114
Studies have found that
higher concentrations of fracking wells are associated with
higher inpatient hospitalisation for cardiac or neurological
problems.115
Transforming fossil fuels into plastic resins also
releases carcinogenic and other pollutants with documented
negative impacts on the nervous and reproductive systems,
among other adverse health impacts.116
Incineration of plastic, particularly with inadequate
emission standards or uncontrolled burning,
releases harmful substances which can travel long
distances.117
These substances are linked to adverse human
health impacts including respiratory problems, cancers,
and neurological damage.118
For example, dioxins and
related compounds are formed when one of the most widely
produced synthetic plastic polymer polyvinyl chloride (PVC)
is burned in open fires. At least 30 of these compounds are
considered harmful to human health, with evidence that they
can damage the brain and disrupt hormones.119
The toxins
from incineration and open burning can travel long distances
and persist in the environment for many years. Humans then
ingest these substances via plants and animals that have
accumulated them.120
Plastic production, incineration, and open burning can pose
significant threats to human health. However, the extent to
which these threats are being realised in the population is
still largely undocumented.
Evidence of human exposure to microplastics is
growing, but scientific understanding of the health
implications is still limited.
Humans face exposure to microplastics in all aspects
of daily life. It is in the air people breathe, the water
they drink, the food they eat, and the clothes they wear. In
particular, microplastic fragments have been detected in tap
and bottled water, honey, shrimps, and salt among other
human consumption products.121,122,123
Scientific research
has also found the presence of microplastic particles in
human faeces.124
This suggests that humans are inadvertently
ingesting plastic. Furthermore, microplastics have even been
detected in placentas, suggesting the inadvertent ingestion
of microplastics by mothers can expose unborn children to
microplastics.125
However, the link between microplastic ingestion
and negative human health impacts remains a
source of uncertainty. Due to ethical concerns preventing
studies that expose humans to microplastics to study the
health impacts, initial studies have focused on evaluating
the impact of microplastics on marine species and small
mammals.126
One study of mice reported that microplastics
may induce changes in energy and fat metabolism and cause
disruption to the functioning of the nervous system, with
potential implications for human health. Although, current
evidence suggests that the majority of plastic particles are
expected to pass through the gastrointestinal tract without
being absorbed, 127
it has been hypothesised that once
ingested, microplastics could release harmful chemicals that
were ingredients of the initial plastic product or pathogenic
contaminants that the plastic particles have absorbed
while in the environment.128
As this is a relatively new area
of research, the World Health Organization have so far
stated that there is not enough evidence to conclude that
microplastic particles pose a threat to human health.129
WWF INTERNATIONAL 2021
TCoPS

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