plastics and health Flashcards
what is LDPE
low density PE
what is HDPE
high density PE
what are gyres
large accumulation zones of plastic accumulation via winds, tides, currents
what are microplastics
fragments smaller than 5mm added to consumer products (e.g. beads to cosmetics)
breakdown from larger debris
fibres shed from synthetic fabrics
not removed by wastewater treatment
ubiquitious - found everywhere. constant exposure
what are primary microplastics
enter environment as manufactured components
what are secondary microplastics
enter environment through fragmentation and degradation of larger plastics by exposure to UV light, freezing, wind, wave action and abrasion
e.g. breaking C-C bonds
also breakown of synthetic fibres and discharge via wastewater from washing machines
what size are macroplastics
less than 25mm
10 ^0 m
what size are mesoplastics
10^-2 m
what size are microplastics
10^-4 m
what size are nanoplastics
10-6m
main contributors to plastic pollution on land - 3
city dust
tyres
synthetic textile
microplastics in snow
via fourier transform infrared imaging
varnish, rubber, polyethylene, polyamine dominated
what type of additives do micro and nanoplastics have
range of polymer and chemical
what 3 things influence micro and nanoplastic effects
size
shape
surface properties
health hazards of microplastics in the sea
move thru marine web, absorb and give off chemicals and pollutants
plastic ingredients or toxic chemicals can accumulate in environment
examples of toxins that can bind to microplastics - 5
dioxin
persistent organic pollutants -POP
polybrominated diphenyl ethers - PDBE
polychlorinated biphenyls - PCB
Polycyclic aromatic hydrocarbons - PAH
what are HOCs
hydrophobic organic chemicals
what are hydrophobic organic chemicals
can bind to plastics
microplastic surface area
inc SA:volume ration and surface hydrophobicity
what is surface hydrophobicity
adsorption to surface or aborption to particle of plastic
examples of hydrophobic organic chemicals - 4
organochlorine pesticides
polychlorinated biphenyls
polycyclic aromatic hydrocarbons
bisphenol A
what is bisphenol A
super bad hydrophobic organic chemical
used in production of polycarbonate plastics and epoxy resins
can leach from polycarbonate bottles into liquid
linked to hormone disruptions, interferes with production, secretion, transport, action, elimintation
infants and children most vulnerable
plastics are endocrine disrupting compounds - EDCs. how?
plastics that have hydrophobic organic chemicals can translocate from mother to developing fetus in pregnancy - exposure from pre conception and during preg
this causes altered hormonal, metabolic, epigenetic stuff
can lead to PCOS, pre term birth, etc
bisphenol A associations - 4
obesity
CVD
hormone disruption
damage to fetal development
PVC polymers and plastisol associations
pithalate esters:
abnormal sexual development
birth defect
carcinogens - butyl benzyl phthalate and di-2ethylhexyl phthalate
risk of increased sorption of POPs and heavy metals on plastics
inc in antimicrobial resistance genes
risk of long distance transport of floating particles
transport to ecologically sensitive areas
risk of longer retention times of plastics in gut
inc disease risk to mariculture and marine food webs
3 ways we are exposed to plastic
ingestion
inhalation
contact
main 2 sources of ingested plastic
seafood
bottled water
what happens when micro and nanoplastics are ingested - where do they go
pass through tight junctions in body
can be taken up by tissue cells e.g. dendritic cells
go into lymph vessels and nodes, transported around body
easier if damaged intestinal barrier cell lining, enters systemic circulation
cellular uptake mechanisms plastics use - 4
phagocytosis normally
macropinocytosis
receptor mediated endocytosis - clathrin
passive diffusion
ROS and inflammation - plastics
after uptake, plastic enters lysososmes, enter cytoplasm, induce ROS damaging DNA, which induces more ROS
DAMPS released from cell to signal immune cells to battle the plastic
this causes apoptosis or necrosis
