As a developing country, Brazil presents a wide range of environmental risks that can constitute hazards to child health. The country also presents different socio-economic-cultural conditions that could be responsible for determining different vulnerability and susceptibility levels for the population, which can potentiate the effects of the environmental pollutants. The Rio Birth Cohort Study (PIPA project) is a prospective maternal-infant health study, hosted in the city of Rio de Janeiro (Southeastern Brazil), designed to investigate separate and combined effects of environmental chemical pollutants, as well as the interactions between these exposures and sociocultural environment and epigenetic patterns. This paper presents the learned lessons and strategies to address the shortcomings detected from this pilot study. The study population will be all children born at the Federal University of Rio de Janeiro Maternity Hospital from July 1st, 2020 to June 30th, 2021. The estimated population is of 2,500 children. The study will collect social, demographic, and health information from pregnant women and their children up to four years of age. Biological samples from both mothers and newborns will be collected to assess metal, pesticide and plasticizer exposure. All newborns will have their landmarks of physical, neurological, psychological, and cognitive development recorded at specific ages. A pilot study was carried out between September 2017 and August 2018, totaling 142 enrolled pregnant women, leading to 135 (95%) births and the collection of umbilical cord (126-93%,) and mother (139-98%) blood samples, as well as both mother (142-100%) and newborn (54-40%) urine samples and newborn meconium samples (117-86.7%). The study proposes a comprehensive assessment of pre- and postnatal exposure to environmental chemicals at multiple time points in a population living in a highly urbanized developing country. As far as we know, this is the only birth cohort in Brazil specifically designed for this purpose.

The PIPA Project is a prospective birth cohort study based in Rio de Janeiro, Brazil, whose pilot study was carried out between October 2017 and August 2018. Arsenic (As), cadmium (Cd), lead (Pb), and mercury (Hg) concentrations were determined in maternal (n = 49) and umbilical cord blood (n = 46). The Denver Developmental Screening Test II (DDST-II) was applied in 50 six-month-old infants. Metals were detected in 100% of the mother and newborn samples above the limits of detection. Maternal blood lead concentrations were higher in premature newborns (GM: 5.72 µg/dL; p = 0.05). One-third of the infants (n = 17–35.4%) exhibited at least one fail in the neurodevelopment evaluation (fail group). Maternal blood arsenic concentrations were significantly (p = 0.03) higher in the “fail group” (GM: 11.85 µg/L) compared to infants who did not fail (not fail group) (GM: 8.47 µg/L). Maternal and umbilical cord blood arsenic concentrations were higher in all Denver Test’s domains in the “fail group”, albeit non-statistically significant, showing a tendency for the gross motor domain and maternal blood (p = 0.07). These findings indicate the need to further investigate the toxic effects of prenatal exposure to metals on infant neurodevelopment.

Background: Brazil is the largest country in South and Latin America with an accelerated urbanization process, and the city of Rio de Janeiro is the second most populous. The PIPA Cohort Project is the first prospective study investigating the effects of urban exposure to multiple pollutants on maternal–child health in Brazil. Objective: This paper describes the relationship between maternal socio-environmental conditions and newborns’ umbilical cord blood concentrations of metals (lead, arsenic, and mercury). Methods: The study population was a convenience sample of all babies born at the UFRJ Maternity Hospital over a period of 12 months from pregnant women aged 16 or older living in Rio de Janeiro. Demographic, socio-economic, lifestyle, work, and housing variables were collected. Metals concentrations were analyzed in umbilical cord blood using the inductively coupled plasma mass spectrometry technique. Results: There were 844 (93%) eligible births, with 778 (94%) cord blood samples collected. The detection rate of Pb, Hg, and As were 99% (742), 94.5% (708), and 61% (450), respectively. The total green area percentage (PAGT) of urban residence zones was one primary socio-environmental characteristic determinant of high metal exposure (≥median). Newborns living in city zones with lower total green area percentages (PAGT) had equal to or above-median cord blood concentrations of at least one metal (p = 0.026), of lead and mercury (PbHg) at the same time (p = 0.006), or of lead (p = 0.006). The city zones with the worst indicators of greenspace availability also presented human development indexes (HDI) under the city’s mean HDI. Conclusion: The study provides evidence that the lower availability of urban green spaces in residential zones is associated with greater environmental exposure to pollutants (metals) during pregnancy and can constitute a socio-environmental vulnerability indicator.

Resumo Objetivo: Investigar o impacto dos níveis séricos de vitamina D e de cálcio e do uso de substâncias psicoativas durante a gestação no perímetro cefálico de recém-nascidos de uma maternidade. Métodos: Coletaram-se dados por entrevistas, exames laboratoriais e prontuários, envolvendo 844 gestantes. As variáveis de exposição incluíram níveis de vitamina D, de cálcio e uso de álcool, tabaco e drogas na gestação. O desfecho foi o perímetro cefálico, avaliado como contínuo e categórico (<32 cm ou ≥32 cm). Utilizaram-se testes de correlação (r), Kruskal-Wallis, Mann-Whitney e de regressão para estimar riscos, com significância de 5%. Resultados: Das gestantes, 28,4% fumavam, 41% consumiam álcool e 4,6% usavam drogas, 90,3% apresentavam vitamina D insuficiente e 62,5% cálcio abaixo do normal. A maioria dos partos foi através de cesariana (57,3%), sendo 16,1% prematuros, 4% de gêmeos, 51,1% de meninas e 12,8% de bebês com baixo peso. Houve forte correlação entre peso ao nascer e perímetro cefálico (r=0,805; p-valor<0,001), correlação fraca com os níveis de cálcio (r=0,129; p-valor 0,01) e nenhuma com os níveis de vitamina D (r=0,051; p-valor 0,310). Bebês de mães que consumiram álcool (33,77±2,02 cm) e drogas (33,32±1,72 cm) apresentaram perímetros menores (p-valor<0,05) comparados aos de mães que não usaram (34,04±1,99 cm; 33,96±2,02 cm). Prematuridade, gestações gemelares, sexo feminino e baixo peso associaram-se a perímetros menores (p-valor<0,05). Nenhuma variável associou-se ao perímetro cefálico0,05). Conclusão: Bebês de gestantes que usaram álcool, drogas e tiveram baixos níveis de cálcio apresentaram perímetros menores, porém, nenhum fator associou-se a valores abaixo de 32 cm.