Bioaccumulation and biomagnification of PBDEs in a terrestrial food chain at an urban landfill.

Biota samples from the Vancouver municipal landfill located in Delta, BC, Canada, have some of the highest polybrominated diphenyl ether (PBDE) levels reported from North America. We followed a population of European starlings (Sturnus vulgaris) breeding in a remediated area in the landfill to identify exposure routes and bioaccumulation of PBDEs in a simple terrestrial food chain. This population was compared to a reference farm site located 40 km east in Glen Valley. We analyzed samples of European starling eggs and nestling livers as well as invertebrate prey species consumed by starlings for PBDE concentrations. We also collected soil samples from starling foraging areas. All samples from the Delta landfill had higher PBDE congener concentrations compared to the Glen Valley reference site and were dominated by BDE-99 and BDE-47. Stable nitrogen (δ N15) and carbon (δ C13) isotope analysis of starling blood samples and provisioned invertebrates revealed that stable δC13 signatures differed between the sites indicating that the diet of starlings in the Delta landfill included a component of human refuse. Biota-soil accumulation factors (BSAFs) > 1 demonstrated that PBDEs were bioaccumulating in soil invertebrates, particularly earthworms, which were readily accessible to foraging starlings in the landfill. Biomagnification factors (BMFs) calculated from foraged food items and starling egg and liver samples were >1, indicating that a diet of soil invertebrates and refuse contributed substantially to the PBDE exposure of local starlings.

"More than Meets the Eye": When the Neonatal Course May Impact Several Years Out.

CASE: Nadia is a 7-year-old girl who you have followed since her discharge from the Neonatal Intensive Care Unit (NICU). Her parents are here today for an urgent visit with behavioral concerns, such as inattention, hyperactivity, and aggression.Nadia is a former 40-weeker born through vacuum-assisted vaginal delivery at 9 pounds 7 ounces. Her delivery was complicated with shoulder dystocia, which resulted in resuscitation. Her Apgar scores were 1, 3, and 4 at 1, 5, and 10 minutes, respectively. After intubation and stabilization on mechanical ventilation, Nadia was transferred to the NICU. Her neonatal course included systemic hypothermia using "cool cap" for hypoxic-ischemic encephalopathy (HIE) for a duration of 72 hours. She was extubated on day of life 3. She had an occupational therapy consultation for poor suck/feeding, and it quickly improved. She was discharged on day of life 14. On discharge, Nadia was referred to early intervention (EI) and the NICU follow-up clinic. Nadia was followed by EI until 12 months of age and in the NICU follow-up clinic until 18 months of age, as there were no concerns meeting her developmental milestones or her neuromotor development.At this urgent visit, Nadia's parents report that she attended a family child care from 1.5 to 3 years of age, Head Start from 3 to 5 years of age and the local public school from 5 years to present. Since starting child care, Nadia's teachers have reported that she requires a lot of redirection and refocusing, fidgets a lot in class, and can be aggressive toward her peers when unprovoked. Since her parents had not seen these behaviors at home, they thought it was a phase that she would grow out of. However, as they began to work with her to complete school assignments, they noticed that it was very difficult for Nadia to sit still and focus on work. They also struggled in the mornings to get her ready and off to school.The parents bring in Conners scales completed by themselves and her lead teacher, and with these and our clinical observations, we diagnose her with attention-deficit/hyperactivity disorder (ADHD), combined type. We discuss risk factors and ADHD management with her parents. During our discussion, Nadia's father, who has done some reading on ADHD, remembers reading an article about HIE and NICU stay being risk factors for ADHD. He wonders if this affects the choice of management of her ADHD symptoms. How would you address his query?

The Effects of the Organic Flame-Retardant 1,2-Dibromo-4-(1,2-dibromoethyl) Cyclohexane (TBECH) on Androgen Signaling in Human Prostate Cancer Cell Lines.

The effects of the organic flame retardant 1,2-Dibromo-4-(1,2-dibromoethyl) cyclohexane (TBECH) on androgen receptor target gene expression were examined in the human LNCaP prostate cancer cell line. While γ-/δ-TBECH alone led to a significant increase in prostate-specific antigen (PSA) mRNA accumulation, both the α-/-TBECH and γ-/δ-TBECH mixtures repressed androgen-inducible PSA mRNA and protein accumulation in human LNCaP cells. Thus, we hypothesize that isomeric mixtures of TBECH may act as partial agonists of the androgen receptor.

Levels of PBDEs in plasma of juvenile starlings (Sturnus vulgaris) from British Columbia, Canada and assessment of PBDE metabolism by avian liver microsomes.

In this study, the levels of polybrominated diphenyl ethers (PBDEs), HO-PBDEs, and bromophenols were monitored in starling chick plasma samples collected in Delta (British Columbia, Canada) close to the Vancouver municipal landfill and in Glen Valley, a rural area in British Columbia. The in vitro formation of hydroxylated metabolites of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) and 2,2',4,4',5-pentabromodiphenyl ether (BDE-99) was also investigated using starling chick liver microsomes. Total PBDE plasma levels were approximately 60 times higher in starling chicks from Delta than from Glen Valley, suggesting that the Delta site is a major source of PBDEs for the local population of starlings and that PBDEs previously measured in starling eggs are bioavailable to chicks. In both locations, BDE-47 and BDE-99 were the two major congeners present at similar concentrations, suggesting contamination with the Penta-BDE mixture. Among the several possible hydroxylated metabolites of PBDEs monitored in starling plasma, only 2,4,5-tribromophenol was detected and its levels did not exceed 18±7 pg/mL. Also, several hydroxylated metabolites of BDE-47 and BDE-99 were formed by starling chick liver microsomes, but in low amounts. Therefore, our data consistently suggest that oxidative metabolism of PBDEs in starling chicks proceeds at low rate in vivo and in vitro. In conclusion, the landfill located in Delta is a relevant source of bioavailable PBDEs for the local starling population. Because of the limited ability of starling chicks to metabolize PBDEs, these compounds are likely to bioaccumulate in starlings over time. The possible toxicological implications of PBDEs bioaccumulation in starlings are currently unknown and require further research.

Effects of the bioaccumulative polybrominated diphenyl ether flame retardant congener BDE-47 on growth, development, and reproductive success in zebra finches.

This study investigated the effects of the polybrominated diphenyl ether congener, 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) on the growth and development, and subsequent breeding success of exposed zebra finches (Taeniopygia guttata). Using oral dosing procedures and treatments adjusted by weight, we treated newly hatched chicks daily for the first 20-days-post-hatch (dph) with varying treatments of BDE-47 (0, 5, 50, and 500 ng/g bw/day). Weight and tarsal measurements were monitored from hatch to 90 dph, but no differences were observed between treatment groups at any age. Treated females that reached sexual maturity were mated with untreated males; however, again no treatment effects were observed on breeding success. Analysis of tissue samples at 21 dph did indicate that debromination of BDE-47 had occurred resulting in BDE-28 and BDE-17 metabolites.

"More than meets the eye": when the neonatal course may impact several years out.

CASE: Nadia is a 7-year-old girl who you have followed since her discharge from the Neonatal Intensive Care Unit (NICU). Her parents are here today for an urgent visit with behavioral concerns, such as inattention, hyperactivity, and aggression.Nadia is a former 40-weeker born through vacuum-assisted vaginal delivery at 9 pounds 7 ounces. Her delivery was complicated with shoulder dystocia, which resulted in resuscitation. Her Apgar scores were 1, 3, and 4 at 1, 5, and 10 minutes, respectively. After intubation and stabilization on mechanical ventilation, Nadia was transferred to the NICU. Her neonatal course included systemic hypothermia using "cool cap" for hypoxic-ischemic encephalopathy (HIE) for a duration of 72 hours. She was extubated on day of life 3. She had an occupational therapy consultation for poor suck/feeding, and it quickly improved. She was discharged on day of life 14. On discharge, Nadia was referred to early intervention (EI) and the NICU follow-up clinic. Nadia was followed by EI until 12 months of age and in the NICU follow-up clinic until 18 months of age, as there were no concerns meeting her developmental milestones or her neuromotor development.At this urgent visit, Nadia's parents report that she attended a family child care from 1.5 to 3 years of age, Head Start from 3 to 5 years of age and the local public school from 5 years to present. Since starting child care, Nadia's teachers have reported that she requires a lot of redirection and refocusing, fidgets a lot in class, and can be aggressive toward her peers when unprovoked. Since her parents had not seen these behaviors at home, they thought it was a phase that she would grow out of. However, as they began to work with her to complete school assignments, they noticed that it was very difficult for Nadia to sit still and focus on work. They also struggled in the mornings to get her ready and off to school.The parents bring in Conners scales completed by themselves and her lead teacher, and with these and our clinical observations, we diagnose her with attention-deficit/hyperactivity disorder (ADHD), combined type. We discuss risk factors and ADHD management with her parents. During our discussion, Nadia's father, who has done some reading on ADHD, remembers reading an article about HIE and NICU stay being risk factors for ADHD. He wonders if this affects the choice of management of her ADHD symptoms. How would you address his query?

An assessment of in ovo toxicity of the flame retardant 1,2-dibromo-4-(1,2-dibromoethyl) cyclohexane (TBECH) in the zebra finch.

Embryonic toxicity of a brominated flame retardant, TBECH (1,2-dibromo-4-(1, 2-dibromoethyl) cyclohexane) was investigated using the zebra finch (Taeniopygia guttata) as our model. Using in ovo dosing procedures, we injected the technical TBECH compound, consisting of 50:50 α-/ß-isomers, directly into the yolk of freshly laid eggs at concentrations of 2.3-94 ng/g egg. No significant effects were observed in terms of growth or survival for either pre-hatch embryos or post-hatch chicks. Analysis of tissue samples at various developmental stages suggests that α-/ß-TBECH was metabolized rapidly, and thus is unlikely to cause any direct, long-term effects on the development of zebra finch embryos or offspring.