5.4 menezes filho
TRANSCRIPT
High levels of manganese exposure and neurobehavioral effects on children
José Antonio Menezes‐FilhoLaboratory of Toxicology ‐ College of Pharmacy
Federal University of BahiaBrazil
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Background
• High levels of waterborne manganese have been associated with problematic behaviors in school‐aged children (Bouchard, 2007 & Khan, 2011)
• So far, this has not been reported with respect to airborne manganese.
• Lucchini (2011) observed tremor, olfactory and motor changes in adolescents in Brescia, Italy.
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Background• In Bahia, Brazil a ferro‐manganese alloy plant has been
emitting tons of MnO particulate matter since 70’s.
• High exposure levels has been evidenced (Menezes‐Filho, 2009).– Air Mn in PM2.5: 0.151 µg/m3 (range 0.011–0.439 µg/m3 ) (0.05 µg/m3
EPA urban air)
– MnH levels: 15.20 µg/g (1.10–95.50 µg/g) gradient related to atmospheric dispersion.
– Mn water levels: low compared to the WHO guidelines of 400 µg/L (WHO, 2006).
• Inverse associations between LogMnH and intellectualfunction of children and their mothers: (Menezes‐Filho, 2011).– Full‐Scale IQ: β= ‐5.78 (95%CI ‐10.71 to ‐0.21)/ Adj. Nut.St. & Mat. IQ.
– Raven Score: β= ‐2.69(95%CI ‐5.43 to 0.05)/Adj. Age, Income & Educ.3
Objectives
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• We report here the results of the evaluation of children of two communities exposed to airborne Mnfrom a ferro‐manganese alloy plant and its relation with behavioral changes in children.
Methods• Cross‐sectional design• Seventy children (34 boys) age range 6 to 12 years, living in two
communities close to a ferro‐manganese alloy plant in Bahia, Brazil were evaluated.
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Simões Filho Town
Santa Luziavillage
Cotegipe village
Ferro‐alloy Plant
• Hair manganese (MnH) and blood lead levels (BLL) were measured by GF‐AAS (Wright 2006, Montes, 2009).
• The Children’s Behavior Check List (CBCL) Portuguese version validated in Brazil was administered to parents or caregivers and teachers.
• Trained psychologist generated behavioral indices:• Internalizing: withdrawn, somatic complaints, and
anxious/depressed scales) • Externalizing: combines disruptive and aggressive behaviors • Scale for inattention. • Maternal estimated IQ (WAIS‐III)
• Socioeconomic questionnaires were applied to volunteers, after giving consent to participate.
• The study approved by the Federeral University of Bahia ethicalcommittee.
Occiptal hairsampling
GF‐AAS Analysis
Cleaning:0.5% Triton‐X100
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Nitric AcidDigestion
Sociodemographic characteristics of the study population
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Results Boys (n=34) Girls (n=36)
Mean SD Median Min. Max. Mean SD Median Min. Max.Children
Age (years) 9.5 1.6 10.0 7 12 9.4 1.6 10.0 7 12
Z-score HA -0.11 0.86 -0.18 -1.21 2.38 -0.17 1.31 0.00 -3.18 2.60Head circumference (cm) 52.9 1.3 53.0 49.5 56.1 52.6 2.0 53.0 48.2 58.5Blood Lead (µg/dL) 1.2 1.3 0.5 0.5 6.1 1.1 0.9 0.5 0.5 4.0Hair Mn (µg/g) 15.3 9.9 12.1 1.5 48.5 13.9 13.4 12.4 0.5 55.7
Externalizing BehaviorsDisruptive 3.5 3.4 3.0 0 14 2.9 2.8 2.0 0 12Aggressiveness 9.3 5.6 9.0 0 23 9.4 7.6 8.0 0 28
Internalizing BehaviorsAnxiety/depression 4.3 3.2 3.0 0 12 5.4 3.7 5.0 0 16Withdrawn 2.7 2.3 2.0 0 10 2.7 2.2 2.0 0 7
Inattention 6.1 3.5 6.0 0 13 4.9 3.9 5.0 0 13Main caregiver
Mothers 61 87%
Grandmothers 6 9%Others 3 4%Age (years) 35.9 2.1 112 16 62Estimated IQ 86.7 10.9 83 71 117
Results• No significant differences in any sociodemographic and
behavioral index according to children’s sex.
• Median and range of MnH and BLL were 11.48 (0.52 – 55.74) µg/g and 1.1 (0.5 – 6.1) µg/dL.
• Externalizing behaviors were significantly correlated with MnH levels:
– Disruptive: Spearman rho=0.347, p=0.004)
– Aggressiveness: Sp rho=0.326, p=0.006
– Total Externalizing behaviors: Sp rho= 0.359, p=0.002
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Results• Non‐standardized coefficients of LogMnH levels of externalizing and inattention behaviors.
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BehaviorIndices
β 95% CI
Aggressiveness 5.69 (1.91-9.48)
Disruptive 2.07 (0.30-3.85)
Total
Externalizing
8.12 (2.94-13.39)
Inattention 3.35 (1.23-5.47Adjusted for age and sex.
Discussion
• In the USA, Wright (2006) found conitive but no behavioralassociation with MnH on 32 children (11‐14 years) living neara waste disposal site.
• In Quebec, Bouchard (2007) using Conner’s Scale observedsignifcant association beteween MnH and oppositional andhyperactivity scores in 46 children exposed to Mn in the wellwater.
• In Bangladesh, Khan (2011) evaluated 201 children exposed to As and Mn in the well water. Significant associations foundbetween Internallizing (β=0.82) and externalizing (β =2.59) behaviors with logMnW.
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Discunssion
• High exposure to Mn is associated to higher levels of prolactin, which may have an effect on early onset of puberty (Montes et al. 2011).
• Zhang et al. (1995) observed correlation of higher Mn levels with lower serotonin in exposed children compared to controls.
• It has been demonstrated increased impulsivity and violence in youngsters with lower levels of serotonin.
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Conclusions
• Our results suggest that children’s high exposure to airborne Mn may be having detrimental effects on behavior, especially those related with externalizing anti‐social behaviors.
• We hypothesize that excessive Mn exposure may contribute to increased violence, especilay in indiviaduals of vulnerable communities.
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• Children, parents and teachers from Cotegipe and Santa Luzia Communities, Bahia, Brazil.
• Our Collaborators:– Dr. Neander Abreu, ISP/UFBA– Chrissie de Carvalho, ISP/UFBA– Júnia Dutra, FacFar/UFBA– Our team: Sério Prado, Gustavo Viana, Nathália Ribeiro, Juliana
Rodrigues, Diego Andrade, Valu.
• Funding agencies:– FAPESB: research grant– CAPES: travel support
Acknowledgements
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Thank you!