Impact of PCB and p,p'-DDE contaminants on human sperm Y:X chromosome ratio: studies in three European populations and the Inuit population in Greenland.
OBJECTIVE
Recent studies indicate that persistent organohalogen pollutants (POPs) may contribute to sex ratio changes in offspring of exposed populations. Our aim in the present study was to investigate whether exposure to 2,2 ,4,4 ,5,5 -hexachlorobiphenyl (PCB-153) and dichlorodiphenyldichloroethene (p,p -DDE) affects sperm Y:X chromosome distribution.


METHODS
We obtained semen and blood for analysis of PCB-153 and p,p -DDE levels from 547 men from Sweden, Greenland, Poland (Warsaw), and Ukraine (Kharkiv), with regionally different levels of POP exposure. The proportion of Y- and X-chromosome-bearing sperm in the semen samples was determined by two-color fluorescence in situ hybridization analysis.


RESULTS
Swedish and Greenlandic men had on average significantly higher proportions of Y sperm (in both cohorts, 51.2%) and correspondingly higher lipid-adjusted concentrations of PCB-153 (260 ng/g and 350 ng/g, respectively) compared with men from Warsaw (50.3% and 22 ng/g) and Kharkiv (50.7% and 54 ng/g). In the Swedish cohort, log-transformed PCB-153 and log-transformed p,p -DDE variables were significantly positively associated with Y-chromosome fractions (p-values 0.04 and <0.001, respectively). On the contrary, in the Polish cohort PCB-153 correlated negatively with the proportion of Y-bearing fraction of spermatozoa (p=0.008).


CONCLUSIONS
The present study indicates that POP exposure might be involved in changing the proportion of ejaculated Y-bearing spermatozoa in human populations. Intercountry differences, with different exposure situations and doses, may contribute to varying Y:X chromosome ratios.
Tiido
Tarmo
T
Molecular Reproductive Medicine Research Unit, Department of Clinical Sciences, Fertility Centre, Malmö University Hospital, Lund University, Malmö, Sweden. tarmo.tiido@med.lu.se
Rignell-Hydbom
Anna
A
Jönsson
Bo A G
BA
Giwercman
Yvonne Lundberg
YL
Pedersen
Henning S
HS
Wojtyniak
Bogdan
B
Ludwicki
Jan K
JK
Lesovoy
Vladimir
V
Zvyezday
Valentyna
V
Spano
Marcello
M
Manicardi
Gian-Carlo
GC
Bizzaro
Davide
D
Bonefeld-Jørgensen
Eva C
EC
Toft
Gunnar
G
Bonde
Jens Peter
JP
Rylander
Lars
L
Hagmar
Lars
L
Giwercman
Aleksander
A