18 BFRs & PFAs

Question 1

what is the outline of this lecture?

Answer 1

-what are BFRs? what are their applications?
-source and chemodynamics of BFRs
-exposure and toxicity to BFRs
-novel BFRs: what do we know about them?
-what are PFAs? sources and chemodynamics of PFAs
-exposure and toxicity of PFAs

Question 2

what does BFR and PFA mean?

Answer 2

-brominated flame retardants
-polyfluoroalkyl substances

Question 3

what is the definition and statistics of flame retardants?

Answer 3

statistics:
-every year in North America, there are over a million fires reported
-direct losses account for billions in damages

definition
-a substance added or a treatment applied to a material to suppress, or significantly reduce or delay the combustion of the material

Question 4

why has the use of BFRs increased?

Answer 4

due to
-high standards of flame retardancy
-FR industry values at 2.3 billion (USD)

-synthetic polymers, household furniture, electronics
-all more flammable than wood/metal

-BFRs help save lives: extra time to vacate/get out of your burning pants suit

Question 5

what is the global consumption of FRs?

Answer 5

Question 6

what is the chemical reactivity of halogenoalkanes?

Answer 6

Question 7

what are the three subgroups of BFRs?

Answer 7

Question 8

what are PBDE commercial mixtures?

Answer 8

Question 9

what is the physiochemical properties of selected BDFs?

Answer 9

Question 10

what are the major flame retardant exposure pathways?

Answer 10

Question 11

why do we say “they-re everywhere”?

Answer 11

PBDEs are now ubiquitous environmental contaminants:
-indoor and outdoor air
-house and office dust
-rivers and lakes and sediments
-sewage sludge
-food
-biota (terrestrial and marine mammals, fish, humans)
-remote arctic regions (i.e. long-range transport)

Question 12

what was tested in BC?

Answer 12

Question 13

what were the results on exposure and accumulation of BC?

Answer 13

Question 14

what are some new and emerging POPs?

Answer 14

Question 15

what are PBDEs in polar food web?

Answer 15

Question 16

what are the recent trend in legacy BFR (e.g. HBCDD) in the arctic?

Answer 16

Question 17

what are the human exposures to PBDEs?

Answer 17

-breastmilk
-maternal transfer to fetus
-diet (esp., fish, meat, dairy)
-indoor, house and office dust, outdoor air
-occupation

Question 18

what is the dust exposure route?

Answer 18

Question 19

what is the trend in breast milk?

Answer 19

Question 20

what are indoor dust samples?

Answer 20

Question 21

what are children’s exposure to flame retardants?

Answer 21

-indoor environments are often more polluted than outdoor environments (PBDEs in dust&raquo_space;»»> PBDEs in soils)
-children have a high number of hand-to-mouth contacts
-children are physically in contact with many FR treated products

Question 22

what else can cause a major form of exposure?

Answer 22

exposure via e-waste
-estimated 60-80% of global e-waste is important illegally to southeast asia and other underdeveloped parts of the world
-leads to highest reported levels of human exposure to PBDEs

Question 23

what are the graphs of human exposure in e-waste areas?

Answer 23

Question 24

what are the health effects of BFRs?

Answer 24

liver as target organ: penta/octaBDEs
-increased enzymatic activity (phase I and phase II enzymes), increased liver weight, histopathological changes

developmental neurotoxicity:
-likely due to disruption in thyroid hormone signaling

endocrine disruption

Question 25

what is the thyroid?

Answer 25

thyroid: regulates critical homeostatic processes -metabolism, temperature regulation, in utero growth and neonatal development

Question 26

what are thyroid toxicities of PBDEs?

Answer 26

-thyroid regulates processes through signaling hormones hydroxylated PBDEs similar to T4 -potential for interaction with similar targets thyroid toxicities of PBDEs mainly results from disruption of hormone transportation system -major hormone transport protein-transthyretin binding protein (TTR) -i.e. 6-OH-BDE-47, 3x greater binding affinity for TTR than T4 though disruptive for adults, we have several transport proteins for thyroid hormones

Question 27

what are the developmental toxicities of BDEs?

Answer 27

-during pregnancy the mother requires precise concentrations of hormones to orchestrate the complex process of fetal development -developing fetus does not produce T4 until second trimester, and rely on mother as major source of T4 for duration of pregnancy

Question 28

what is the maternal transfer of T4?

Answer 28

-TTR major transport enzyme of T4 to developing fetus-crosses placental barrier -TTR binds hydroxylated PBDEs with greater affinity than natural hormone

Question 29

what are the effects of developmental toxicities?

Answer 29

-new meta-analyses -309 women followed children for 5 years -4.5 points lower IQ -3.3 point increase hyperactivity

Question 30

what are NBFRs?

Answer 30

novel brominated flame retardants -deemed "novel" though many have been in use since 1970s -many compounds are simple derivatives of known BFRs

Question 31

what are the properties of NBFR?

Answer 31

Question 32

what are the total NBFR levels in various aquatic environments around the world?

Answer 32

Question 33

what is the potential toxicity of NBFRs?

Answer 33

Question 34

what are NBFRs in marine polar food webs?

Answer 34

Question 35

what is the summary of BFRs?

Answer 35

Question 36

what is the background of PFAs?

Answer 36

Question 37

what are the uses of PFAs?

Answer 37

Question 38

Question 39

what are the fate and behavior of PFAS?

Answer 39

-extremely persistent, long half-life of many PFAS: >40 years -ionic/short-chain PFAS (e.g. PFCAs, PFSAs) are highly water soluble and non-volatile, transported long-distance by water/ocean currents -neutral PFAS (e.g., FTOH) are volatile, typically found in the atmosphere, and transported long-distance by wind -PFAS undergo abiotic and biotic transformation (e.g., WWTPs) to form more stable perfluoroalkyl products-do not degrade under ambient environmental conditions

Question 40

what are the human exposure and effects of PFAS?

Answer 40

Question 41

what are PFAS regulations in canada?

Answer 41

Question 42

what was the results of the test of arctic indigenous peoples?

Answer 42