A Systematic Review of Children's Environmental ...

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Oct 10, 2015 - Carmen I. R. Froes Asmus 1,2*, Volney M. Camara 1†, Philip J. Landrigan,2,3† Luz Claudio 2†. 1Public Health Institute / School of Medicine, ...
A Systematic Review of Children’s Environmental Health in Brazil

Carmen I. R. Froes Asmus 1,2*, Volney M. Camara 1†, Philip J. Landrigan,2,3† Luz Claudio 2†

Public Health Institute / School of Medicine, Federal University of Rio de Janeiro, Rio de Janeiro / RJ, CEP 21944-970, Brazil. E-mails: [email protected] (V.M); [email protected] (C.A.) 1

Preventive Medicine Department, Icahn School of Medicine of Mount Sinai, New York / NY, ZC 10029, USA. E-mails: [email protected] (L.C.); [email protected] (P.L.); [email protected] (C.A.). 2

Arnhold Global Health Institute, Icahn School of Medicine of Mount Sinai, New York / NY, ZC 10029, USA. E-mails: [email protected] (P.L.). 3



These authors contributed equally to this work.

*Author to whom correspondence should be addressed: Carmen I. R. Froes Asmus; E-Mails: [email protected] ; [email protected] Tel.: +1 9179357566; +1 212 8257065.

ABSTRACT

Background: In the region of the Americas, approximately 100.000 children under age of 5 years die each year due to environmental hazards. Brazil, due to its size and wide-range of environmental challenges, presents numerous hazards to children’s health. Objective: to review the scientific literature about the exposure of children to environmental pollutants in Brazil, having as core question the existence, or not, of a broad and solid knowledge about this exposure and its impact on Brazilian children’s health. Methods: A systematic review of the scientific literature was done without language restrictions and time of publication (years). The literature search was conducted in the following key resources: PubMed (MEDLINE), Scopus and Web of Science with the MeSH Terms: Environmental exposure AND Brazil (filters: Human, Child (birth - 18 years) and Affiliation Author). The Virtual Health Library was also employed to access the databases Scielo and Lilacs. The search strategy was [DeCS Terms]: Child OR adolescent AND Environmental exposure AND Brazil. Findings: Health effects associated with exposure to environmental pollutants were reported in 74 studies, during the period between 1995 and 2015. The most frequently cited effect was hospital admission for respiratory causes including wheezing, asthma and pneumonia in children living in areas with high concentrations of air pollutants. A broad spectrum of possible health effects was found such as prematurity, low birth weight, congenital abnormality (cryptorchidism, hypospadia, micropenis), poor performance in tests of psychomotor and mental development and behavioral problems. Exposure to pesticides in uterus and postnatal was associated with a high risk of leukemia in children younger than 2 years old. Conclusions: Results show that there is a need in Brazil for stricter monitoring of pollutant emissions and for health surveillance actions especially among vulnerable populations such as these children.

Keywords: child; environmental exposure; environmental health; environmental pollutants; children’s health. INTRODUCTION

According to the World Health Organization, 25% of the burden of disease in Latin America and the Caribbean can be attributed to poor environmental quality. 1 In this region of the Americas, nearly 100,000 children under age of 5 years die each year due to environmental hazards and the proportionate mortality of children, under age of 14 years, from diseases related to poor environmental conditions is 33% for respiratory diseases, 32% for diarrheal diseases, 26% for injuries, 7% for cancers and 2% for vector-bone diseases.2 This condition adds important economic costs to countries of Latin America.3 Labord et al 4 in a review of the influences of the environmental factors on children’s health in Latin America observed that there are traditional and newer environmental risks to children’s health. The traditional environmental risks include drinking – water contamination and indoor air pollution, among others. The newer hazards are urban air pollution, climate change, exposure to toxic chemicals like heavy metals, asbestos and pesticides, and hazardous and electronic waste (e-waste). The authors pointed out that two important environmental conditions have had a special impact upon the children’s health: the crescent urbanization throughout the world, especially in Latin America (“72% of the population living in urban centers”) and the huge rise in the use and consumption of chemicals products.

Brazil is one of the countries of the region of the Americas that embrace wide-ranging risks and conditions that can constitute a hazard to children’s health. The under five children’s mortality rate (in 1.000 born live) is 15.9% but, due to the ample intraregional developmental differences of the country, this rate achieves almost 20% in the lesser developed regions of the North and Northeast.5

According to the Brazilian Institute of Geography and Statistic, the percentage of population living in an urban area (related to total population) increased by 31.24 in 1940 to 84.36 in the year of 2010.6 Indeed, more than 80% of the Brazilian population lives in urban areas. Regarding the consumption of chemical products in Brazil, the annual commerce of pesticides increased by around 3kg/ha (Kilogram of active compound per hectare of planted area) in the year 2000 to near 7Kg/ha in 2012. The higher proportion of these compounds (60%) is classified as a dangerous product (class III). In this scenario, this study had the objective to review the scientific literature about the exposure of children to environmental pollutants in Brazil. The core question concerns the existence, or not, of a broad and solid knowledge about this exposure and its impact on Brazilian children’s

health. This study addressed this issue in the context of the process of the development of the Latin America countries.

METHOD

A systematic review of the scientific literature was done in the international and national (Brazilian) journals. Technical reports were not included. The eligibility criteria were two: 1 - the study population was constituted of Brazilian children, from birth to 18 years old, and in the intrauterine period (studies including total population were added when they provided individualized age–specific data); 2 - studies on exposure of children to environmental agents (only chemicals). Articles about biological agents, associated with sewage and bad quality of drinking water or as indoor air pollutants (such as bacteria, mould, fungus, etc) were excluded. There were no restrictions regarding design and outcomes of the studies.

Multiple computerized resources were searched without language restrictions. Documents only printed were not included. There was no limit to time of publication (years). The literature search was conducted in the following key resources: PubMed (MEDLINE), Scopus and Web of Science with the MeSH Terms: Environmental exposure AND Brazil (filters: Human, Child (birth - 18 years) and Affiliation Author). The Virtual Health Library was also employed to access the databases Scielo and Lilacs that include many Brazilian journals that are not incorporated into one another. The search strategy was [DeCS Terms]: Child OR adolescent AND Environmental exposure AND Brazil.

Two examiners, independently, did the evaluation of references met in the literature search.. Each examiner read the titles and abstracts based on the two eligibility criteria named above. A third examiner evaluated the abstracts on which the two examiners disagreed. The two examiners read the full texts of abstracts approved by both to confirm the eligibility of the studies. Both examiners evaluated the full texts of studies selected according to the categories: design of study, region of the study, age sub-group, environmental pollutants and ascertainment of outcome. In the 4 databases 783 references were identified being 528 in PubMed- Medline, 130 in Scopus, 4 in Web of Science and 121 in Virtual Health Library. Two examiners selected 206 abstracts to read of full texts and excluded 577 abstracts. They disagreed regarding 10 abstracts. The third examiner evaluated these 10 abstracts and excluded 09 abstracts. One abstract was included to read in the full text. The search of the references added 6 more articles. The 213 articles were read in full and 164 were selected for analysis. Below is the flowchart of the selection of studies for systematic review (Figure 1). The results are presented as follows.

Figure 1: Flowchart of the selection of the studies for systematic review. 783 studies identified 577 studies were excluded after reading of title and abstract: - 327 studies on sewage and bad drink water quality. - 147 studies on biological agents like indoor air pollutants. - 60 studies did not address Brazilian children. - 43 studies excluded like replicated.

206 studies selected by both two examiners 01 study was included evaluation by a third examiner.

after

6 studies were included after search of references.

207 studies selected to reading of full texts

213 studies were read in full texts 49 studies were excluded: - 30 not specifically about Brazilian children. - 19 not about chemical pollutants. - One study was a “Comment on”.

164 studies were selected at end

RESULTS

The studies addressed different pollutants in each of the regions of Brazil. In the Amazon region (North and West regions), the studies encompassed mainly the exposition to metals and air pollutants. In this region, there has been a massive gold mining with the use of mercury. Additionally, a deforestation process has been happening because of the burn of forests to convert into farmland or pastures. The Southeast region, where the two largest metropolitan areas are located - Sao Paulo and Rio de Janeiro, has the higher level of urbanization and industrialization of the country. The majority of the studies were carried out about air pollutants arising from vehicle traffic and industrial emissions as well as most of the studies on exposure to other metals (except mercury). The children’s exposure to pesticides has been studied in almost all regions of the country. Nevertheless, this review was not able to find studies performed in the West region, where the use of pesticides has been increasing significantly due to the expansion of soybean production. Health effects associated with the exposure to environmental pollutants were reported in 74 studies. The main effect described was daily hospital admission for respiratory causes (18) which is in accordance with the large number of studies about exposure to air pollutants. A broad spectrum of possible health damage was investigated about other pollutants, as metals and pesticides: prematurity, low Apgar score, low birth weight, neonatal deaths, alterations in cognitive function, neurobehavioral performance and congenital defects, among others. The Figure 2 presents a summary of a number of studies according to categories of evaluation: the environmental agent researched by the study, the design of the study, the region of the country where the study was done, the age sub-group in which the effects of exposure to pollutant were studied and the tools used to the ascertainment of outcome.

Figure 2: Number of studies according to categories of evaluation. ENVIRONMENTAL AGENT

Metals

Pesticides

Others*

19 6 CaseReview Risk Cohort control assessment 33 17 13 11 1(11 studies) REGION of country Amazon region Northeast South Multicenter (West and North) 67 51 16 7 2 Age - group Fetus Child Adolescent Children and Adolescents (pregnancy) (0–11 y) (12–18 y) 32 77 6 23 Ascertainment of Statistical analysis ** No Statistical analysis 153 4 outcome Environmental sample No Environmental sample 16 141 Only Biological markers Biological markers and No Biological markers environmental samples 54 6 53 Only Health Effects Health Effects and Biological markers 24 50 *Others issues: 1-electromagnetic fields, 1- coal dust, 1- Fluoride intake, 1 - refinery and chemical fertilizers, 1 – organic solvents. **Accomplishment of adjustment to at least one confounding factor in 5 studies, and adjustment to at least three confounding factors in 148 studies. DESIGN of study

72 Crosssectional 69 Southeast

AIR Pollutants 43 Ecologic

Specific Environmental Health Threats to children in Brazil Air pollution

In Brazil, there are two main types of air pollutants sources and they are related to regional characteristics. The first is the automotive emissions and the industrial sources, in the large urban areas of the country. The second is the burning of biomass (forests) to make space for agriculture or cattle rising, in the Amazon region, that encompasses the West and the North regions of the country. Most of the studies were performed in urban areas. However, in both, urban and biomass burning areas, an association between the exposure to air pollutants and an increase in the hospital admissions for respiratory causes was reported. The studies also demonstrated a higher incidence of acute cases of wheezing, asthma and pneumonia, and of the risk of low birth weight.

There were 17 ecological time series studies done in urban areas (largest or medium cities) of Southeast region and two done in burning biomass areas of Amazon region. They used the databases of Department of Informatics of Health System of Brazil (DATASUS) and the information about the concentrations of air pollutants produced by the air monitoring system of the Environmental Ministry of Brazil. All these studies recorded an increase in hospital

admissions for respiratory causes correlated with the concentrations of air pollutants. The Figure 3 presents a summary of main results.

Some studies reported an increase of risk of wheezing, asthma and pneumonia in groups of children and adolescents living in areas with higher concentrations of nitrogen dioxide (NO2) and ozone (O3). The odds of occurrence would be of 2.01 to 3.3 times higher for wheezing, 7,8,9 1.7 to 1.9 times higher for asthma9 and 1.2 to 2.5 times higher for pneumonia 9. The effects of biomass burning on flow expiratory peak (PEF) of children were reported in 3 studies10,11,12. All they observed a PEF decrements associated with the exposure to particulates (PM10, PM2.5 or Black Carbon) with the worst reduction in younger children and occurrence of cumulative and “lagged” (3, 4 or 5 days) effects. In two studies carried out in Rio de Janeiro13 and Sao Paulo14 were related decrease in lung function of children, even with acceptable levels of PM10 and NO2, most of the time. Figure 3_ Hospital admissions for respiratory causes correlated with the concentrations of air pollutants. Summary of main results related by studies carried out in urban and burning biomass areas of Brazil. AUTHORS CONTEXT MAIN RESULTS de Souza JB et al 15 Castro et al 16 Cesar et al 17

Souza SIV et al 18

Moura M et al 19

Nascimento LFC et al 20 Conceiçao GMS 21

Braga et al 22 Gouveia N; Fletcher T. 23 Amâncio CT; Nascimento

Hospital admissions for respiratory disease from Jan 1, 2005 to Dec 31, 2010. Metropolitan region of Vitoria, Southeastern Brazil. Daily records on outpatient treatment for asthma**** from Jan 1, 2001 to Dec 31, 2003. Metropolitan region of Vitoria, Southeastern Brazil. Hospital admissions for respiratory disease from Aug 1, 2011 to Jul 31, 2012. Burning of sugar cane plantation in a medium-sized city in Southeastern Brazil. Hospital admissions for respiratory disease from Sept 2000 to Dec 2005. Municipality of Rio de Janeiro, Southeastern Brazil. Emergency pediatric consultations for respiratory symptoms from Apr 1, 2002 to Mar 31, 2003. Municipality of Rio de Janeiro, Southeastern Brazil.

There was between 2.0% - 3.0% increase in the RR estimated for every 10:49µg/m3 increase in levels of the PM10. The levels of concentration of pollutants studied did not exceed the primary standard of air quality recommended by CONAMA or the limits set by WHO. Out of a total of 84districts in the city, 16.5% showed an asthma rate greater than 20% during the study period. Air pollution levels were relatively low when compared to the Brazilian legislation and WHO guidelines. Only mean PM10 and NO2 exceeded the annual quality standard. Exposure to PM2.5 was related with RR of hospitalization of 1.008 (lag 1) and of 1.009 (lag 3). The increment of 10µg/m3 in PM2.5 increases the RR between 7.98.6%. The authors did not perform a seasonal analysis of exposure related to the period of burning sugar cane (April to November) and considered that the pollution arising from motor vehicles may have contributed to the results observed. The mean daily concentration of PM2.5 did not exceed the limits set by CETESB. For an increase of 10 μg/m3 of PM10 daily levels was observed an increase of risk of hospitalization both, under 1 year old (2.265%; p