15 PPCPs Flashcards
what is the outline of this lecture?
-hazard identification: are there potential risks to human and ecosystem health?
-exposure assessment: who is exposed, how are they exposed, at what levels are they exposed?
-toxicity assessment: what toxic effects are occurring, if any, in humans and wildlife?
-risk management: what regulations and policies are being developed?
PPCPs are an __________
emerging issue
what is the persistence of PPCPs?
-degrade relatively rapidly in the environment
-show low bioaccumulation
-do not “biomagnify” through food chains
-generally, are not acutely toxic
-most are synthetic but usually do not have any halogens (Cl or Br)
but
-may have biological effects at very low doses (sublethal)
-may be “persistent” due to high loading into aquatic environment (will always find amounts in samples due to regular discharge)
what is the term for the persistence of PPCPs?
pseudopersistence
-chronically high levels in the environment
what does PPCPs stand for?
pharmaceuticals and personal care products
what are the domestic sources of PPCPs?
what are agricultural sources?
livestock production: produced en masse so more prone to disease
-hogs
-cattle
-chickens
-sheep
animals are treated with
-antibiotics (therapeutic, prophylactic)
-hormones
-antiparasitics
-growth promoters
what do agriculture sources get into the environment?
biosolids from animals are used as fertilizers on the fields
-or put into landfills
what are aquaculture sources?
to treat cultured fish (to keep free of disease)
inputs of:
-antibiotics
-anti-parasitics
what are the sources and fates of pharmaceuticals?
which countries have the most pharmaceuticals int he environment?
even most modern water treatment systems cannot clear out all pharmaceuticals
what are the environmental concentrations of PPCPs?
what are the personal care products in the environment?
-fragrances (e.g. synthetic musks)
-suntan lotion and sun blocks
-skin cream
-insect repellent (e.g. DEET)
-antibacterial agents (e.g tricolsan, which is found in the highest levels)
what are synthetic musks?
-synthetic musks emulate the odour but not the structure of the expensive natural product
-polycyclic musks (ex: HHCB)
-nitro-musks (ex: Musk Xylene)
-synthetic musks are relatively lipophilic and bioaccumulate in fish downstream of urban areas
what was the results on the research of synthetic musks?
whether they bioaccumulate or not
what are the pharmaceuticals in the environment?
-synthetic hormones (e.g. estrogens, thyroid replacement)
-analgesics and anti-inflammatory (e.g. NSAIDs)
-antibiotics
-antacids and ulcer drugs
-blood lipid regulators (reduce cholesterol)
-cardiac drugs (e.g. beta-blockers)
-anti-depressants and psychotherapy drugs
-anti-epileptics
-anti-neoplastics (cancer chemotherapy)
what is the results of the bioaccumulation of PPCPs in fish?
BAF is the bioaccumulation factor
-ratio of concentration in fish versus conc in water
what did we test in saskatoon?
what is the table of examples of adverse effects of certain pharmaceuticals in the environment?
trends
-reproductive effects through endocrine disruptors
-also cause growth effects
-also behavioural effects (affects mating, migration, hunting)
what are the impacts of PPCPs on wildlife?
PPCPs generally not acutely toxic
however potential for:
-responses not predicted by effects on humans:
1. diclofenac and vultures in India
2. synthetic estrogen (ethinylestradiol)
-biological responses at low doses/concentrations
what is the asian vulture crisis?
-catastrophic decline in numbers of 3 vulture species in last 25 years (90% decline in some areas)
-vulture declines leading to ecosystem disruption with human health implications
-vultures dying from build-up of uric acid (called visceral gout), which does not occur in humans
-uric acid in the main nitrogenous waste in birds, this buildup effects kidney function
-decline attributed to diclofenac (a NSAID), which is used to treat cattle in Asia (considered a veterinary drug)
what was looked at in the UK?
huge increase in raw sewage released into UK waterways and sea, the data revealed:
-many sewage effluents throughout the UK are estrogenic to fish
-persistent in river for considerable distances downstream
-high proportion of river flow in UK comprised of treated sewage effluent
there is not body of water in the UK where fish are not displaying effects of exposure to estrogenic chemicals
what are the sources of environmental estrogens?
many sources of environmental estrogens, including:
-pharmaceuticals (oral contraceptives, hormone replacement therapy)
-natural (estradiol, estrone, estriol) (which are still active through urine)
-detergents (nonionic surfactants, mainly alkylphenol polyethoxylates)
what were the results in the species studied in the UK?
species studied: roach, bream, chub, gudgeon
-increased vitellogenin in males is an indication of feminization (which is in the plasma)
-vitellogenin is a female-specific, estrogen dependent (stimulated by estrogen) egg yolk protein precursor
-induces intersex: predominantly feminization of males
-intersex fish have reduced reproductive capacity (indicator of infertility)
-more intersex fish=decreases in population
what was the testing in lake 260?
lake 260: estrogen addition lake by Dr. Karen Kidd and colleagues
-34 ha in surface area
-maximum depth of 14m
-contain well-defined fish populations
-long-term records on plankton and water quality
-wanted to see what happens when they contaminate the lake with levels of estrogens found in the environment
what were the results from lake 260?
collapse of a fish population after exposure toa synthetic estrogen
findings:
-decreased diversity in algal community
-decreased fecundity (# of eggs) and abundance of zooplankton
-intersex (presence of ovarian follicles in testicular tissue) in male fathead minnows and lake trout
-reproductive failure in fathead minnows
-decreased hatching success of green frogs
-intersex in tadpoles
human health hazards associated with exposure to (potential human impacts):
-PPCPs in drinking water
-PPCPs in food
-development of antibiotic resistant microorganisms in the environment (the major concern)
what is the human health risk assessment of PPCPs in drinking water?
lifetime average daily dose (LADD) estimates based on drinking 2L of water/day for 70 years
using the worst-case scenarios and the highest levels of drugs detected in drinking water
-lifelong water consumption would lead to pharmaceutical exposure <10% of a daily medical dose
-considered to be a non-issue by many people based on these calculations
is there uptake into plants? is it a risk to human health?
19 commonly occurring PPCPs-> vegetable plant irrigated with tertiary treated municipal wastewater
-without (or with fortification of each PPCP at 250 ng/L)
-plants were irrigated until harvest
what is the PPCP concentrations in tertiary treated wastewater and fortified water?
what is the estimation of dietary intake?
estimation of dietary intake= C x D x T
-C=PPCP concentration in the edible tissue of vegetables (ng/g)
-D= per capita daily consumption of fresh vegetables (g/day)
-T= exposure time (day)
conclusion: human exposure to PPCPs through daily consumption of these PPCP-contaminated vegetables is likely to be small
what does UNEP consider a major problem?
people around the world are unknowingly being exposed to water laced with antibiotics, which could spark the risk of drug-resistant pathogens and potentially fuel another global pandemic
what is the contribution of wastewater to antimicrobial resistance?
-antimicrobial resistance (AMR) is a major health issue that has raised major concern globally
-wastewater from pharmaceutical manufacturing plants, and untreated hospital and municipal effluents are major contributors to AMR
-current wastewater treatment processes have limited success in removing microbes with AMR
what are we doing about regulating PPCPs in the environment?
risk management options
what are the risk management options?
-pharmaceuticals are important for health of humans and for use in agriculture and aquaculture
-personal care products and domestic products are economically important
management strategies:
-disposal programs for out-of-date drugs
-better treatment of domestic sewage
-better treatment of livestock waste
-BMPs for application of manure and biosolids
-regulated of selected compounds
what are the regulatory responses?
EU: “trigger value” of 10 ng/L (surface water) for human pharmaceuticals or 1ug/kg (soil) for veterinary medicines for ERA of PPCPs
USA: “trigger value” of 1 ug/L preludes most human pharmaceuticals from assessment
Canada: Health Canada and Environment Climate Change Canada have responsibilities for the development of ERA procedures under CEPA
what is the ERA process in canada?
manufacture or import of pharmaceuticals (new substances) in a quantity of >1000kg/year
-PEC= predicted exposure concentration
-PNEC= predicted no effect concentration
-if ratio is above 1, than there is potential risk
