PRENATAL EXPOSURE TO MERCURY AND EFFECTS ON BIRTH OUTCOMES OF WOMEN - - PowerPoint PPT Presentation

G A I T R E E K . B A L D E W S I N G H 1 , 4, J E F F R E Y K . W I C K L I F F E 3, E D W A R D D . V A N E E R 1, M A U R E E N Y . L I C H T V E L D 3, C O R N E L I S W . Z I J L M A N S 2 , 3 , 4

1 M E D I C A L M I S S I O N P R I M A R Y H E A L T H C A R E S U R I N A M E , S U R I N A M E 2 S C I E N T I F I C R E S E A R C H C E N T E R S U R I N A M E / A C A D E M I C H O S P I T A L P A R A M A R I B O , P A R A M A R I B O ,

S U R I N A M E

3 T U L A N E U N I V E R S I T Y S C H O O L O F P U B L I C H E A L T H A N D T R O P I C A L M E D I C I N E ,

G L O B A L E N V I R O N M E N T A L S C I E N C E S D E P A R T M E N T , N E W O R L E A N S , U S A

4 F A C U L T Y O F M E D I C A L S C I E N C E S , A N T O N D E K O M U N I V E R S I T Y O F S U R I N A M E

PRENATAL EXPOSURE TO MERCURY AND EFFECTS ON BIRTH OUTCOMES OF WOMEN FROM SURINAME’S INTERIOR

DISCLAIMER

This work is supported in part by the National Institutes

• f Health (NIH) Fogarty International Center (grant

numbers R24TW009570, R24TW009561, U01TW010087, and U2RTW010104)

The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

OBJECTIVES

• Background
• Methods
• Results
• Discussion
• Future directions

BACKGROUND

• Mercury (Hg) has high toxic potential - especially for

developing children – and is widely used in Suriname’s interior for artisanal gold mining

• Suriname is a middle upper income country in the north-east
• f South America
• The study population is a subset of the Caribbean Consortium
• f Environmental and Occupational Health environmental

epidemiologic cohort study (CCREOH) aimed at examining the effects of chemical and non-chemical stressors on birth

• utcomes and pediatric neurodevelopment

STUDY AIM

• To determine prenatal Hg exposure and explore the

potential association of Hg exposure and birth

• utcomes in pregnant women living in Suriname’s

interior

• Objectives:
• measure the Hg level in

Interior pregnant women

• analyze the association

between Hg level and birth outcome

MEDICAL MISSION

• White dots MM

health centers

• Population:

± 50.000

• 15 recruitment

areas (red dots)

METHODS

• Hair samples from pregnant women were collected

and analyzed for total Hg using Cold Vapour Atomic Absorption Spectrometry (CVAAS)

• Data on birthweight (BW), and adverse birth
• utcomes categorized as low birthweight

(LBW<2,500g) and preterm birth (PTB<37 weeks) were collected from pregnant women seeking care at the Medical Mission health centers

• Women were prospectively recruited from April

2017-December 2018

METHODS- CONT’D

• 76 live births out of 79 singleton births were included
• 2 stillbirths and 1 miscarriage
• Simple correlation analysis between hair-Hg and BW

treating both as continuous variables

• Exposures were categorized as below or above the

median

• Fisher’s exact test and odds ratios to evaluate

associations with LBW and PTB

RESULTS TOTAL HAIR HG PER REGION

Paramaribo Nickerie Interior 2 4 6 8 10

Location THg in Hair (µg/g) n=525 n=192 n=165

USEPA Action Level

a a b

• Total mercury in hair from pregnant women in Suriname
• Letters indicate significant differences between regions

at p<0.0001 (Kruskal-Wallis)

• USEPA action level 1.1 µg/g hair

RESULTS HAIR HG INTERIOR

Table 1. Hair Hg concentration of interior women

• Adverse birth outcomes:
• 8.6% LBW
• 15.2% PTB

Median (ug/g) Min Max 25th percentile 75th percentile [Hg] in hair 2.42 0.6 18.20 1.55 6.64

RESULTS HAIR HG EXPOSURE LEVELS BY AGE (1)

Age (yrs) Below median (%, n ) Above median* (%,n) 16 -19 5.3 (4) 7.9 (6) 20 - 24 11.8 (9) 15.8 (12) 25 - 34 15.8 (12) 19.7 (15) 35 - 44 14.5 (11) 7.9 (6) ≥ 45 1.3 (1) 48.7% (37) 51.3% (39) *71.8% of the Indigenous women were above the median

53.8% live in far remote areas only accessible by air

Table 2. Age distribution in the study population (n=76)

RESULTS HAIR HG EXPOSURE LEVELS BY AGE (2)

16 - 19 yrs. 20 -24 yrs. 25 -34 yrs. 35 - 44 yrs. ≥ 45 yrs. below median 5.3 11.8 15.8 14.5 1.3 above median 7.9 15.8 19.7 7.9 5 10 15 20 25 percentage (%)

RESULTS TOTAL HAIR HG COMPARED TO USEPA ACTION LEVELS

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00 20.00 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63 65 67 69 71 73 75 Hg in har (ug/g) Number of participants n= 76

Hair Hg levels (ug/g)

Hg in Hair (ug/g) Median (ug/g) USEPA action level

RESULTS STATISTICAL TESTS

• There was no significant correlation between
• Hair Hg and LBW (Fisher's exact test, p<0.43,

OR=0.45 95%CI--0.08-2.04) or

• Hair Hg and PTB (Fisher's exact test, p<0.51,

OR=0.59 95%CI--0.18-2.12).

DISCUSSION

• Hair Hg levels in the interior are well above the USEPA

action levels

• Even though interior women have higher Hg

concentrations compared to the coastal area, prevalence of adverse birth outcomes is lower than the coastal area; health system MM

• High Hg is most likely due to consumption of

contaminated food, predominantly locally caught fish

• Our results are consistent with the literature regarding

exposure to Hg during pregnancy at these concentrations

FUTURE DIRECTIONS

• The findings related to birth outcomes in this sub-

cohort will be validated by ongoing analyses of the larger study cohort of the interior (n=200)

• Ongoing monitoring of Hg in both humans and fish

is necessary to ensure the effectiveness of public health risk management

• Suriname has no national standards on Hg

concentration levels in blood or hair

ACKNOWLEDGEMENTS

• We are extremely thankfull to all the women who

took part in this study, Medical Mission’s health workers for there help in recruiting, and the Meki Tamara research team

• A special thanks to my promotors
• Dr. Wickliffe
• Dr. Lichtveld
• Dr. Zijlmans and
• Edward van Eer, MPH, former director of the Medical Mission