Systematic Review: Neurodevelopmental Benefits of Active/Passive School Exposure to Green and/or Blue Spaces in Children and Adolescents

Today more than half of the world's population lives in urban areas. Children spend about 40 h a week in the school environment. Knowing the influence of school exposure to green/blue spaces could improve the children's health, creating healthier environments and preventing exposure to legal/illegal drugs. This systematic review summarized the main results of published studies on active or passive exposure to green or blue spaces in different domains of child neurodevelopment. In August 2022, five databases were searched and twenty-eight eligible studies were included in the analysis. Cognitive and/or academic performance was the most frequently studied (15/28). Most studies evaluate passive exposure to green/blue spaces (19/28) versus active exposure (9/28). Only three studies addressed the relationship between blue space and neurodevelopment. The main results point toward mixed evidence of a protective relationship between green/blue space exposure and neurodevelopment, especially in improving cognitive/academic performance, attention restoration, behavior, and impulsivity. Renaturalizing school spaces and promoting "greener" capacities for school environmental health could improve children's neurodevelopment. There was great heterogeneity in methodologies and adjustment for confounding factors across studies. Future research should seek a standardized approach to delivering school environmental health interventions beneficial to children's development.

Looking Towards 2030: Strengthening the Environmental Health in Childhood-Adolescent Cancer Survivor Programs

Childhood and adolescent cancer survivors (CACS) are a high-risk population for non-communicable diseases and secondary carcinogenesis. The Environmental and Community Health Program for Longitudinal Follow-up of CACS in the region of Murcia, Spain, is an ongoing pioneering program that constitutes a model for social innovation. This study aims to present the program tools and protocol as a whole, as well as a profile of the incidence, survival, and spatiotemporal distribution of childhood cancer in the region of Murcia, Spain, using 822 sample cases of cancer diagnosed in children under 15 years of age (1998-2020). While the crude incidence rate across that entire period was 149.6 per 1 million, there was an increase over that time in the incidence. The areas with a higher standardized incidence ratio have shifted from the northwest (1998-2003) to the southeast (2016-2020) region. Overall, the ten-year survival rate for all tumor types was 80.1% over the entire period, increasing the five-year survival rate from 76.1 (1998-2003) to 85.5 (2014-2018). CACS living in areas with very poor outdoor air quality had lower survival rates. Furthermore, integrating environmental health into clinical practice could improve knowledge of the etiology and prognosis, as well as the outcomes of CACS. Finally, monitoring individual carbon footprints and creating healthier lifestyles, alongside healthier environments for CACS, could promote wellbeing, environmental awareness, and empowerment in order to attain Sustainable Development Goals for non-communicable diseases in this population.

Confirmation of radiant catalytic ionization efficacy for airborne SARS-CoV-2 elimination indoors using "COVID19 traps"

Radiant catalytic ionization (RCI) is a novel technology that uses the appropriate wavelength (240-260 nm) and the phenomenon of photo-oxidation leading to permanent removal of viruses, bacteria, and fungi. Here, two analyses were performed. The first of them was a complete analysis of environmental biosecurity in a hospital environment. The second one was a longitudinal study with 40 patients with confirmed COVID19 and high viral load to assess the efficacy of RCI technology eliminating airborne SARS-CoV-2 indoors. A significant decrease in the number of bacteria and fungi colony-forming units (CFUs) was found in rooms with RCI when compared with rooms without it (p=0.03 for both of them). In the second part of the study, 16 samples out of 40 (40%) were positives when RCI technology was absent; whereas, these samples were negative when the equipment was on. Incidence rates (IR) with their Poisson 95% Confidence Intervals (CI) were calculated as the number of positive tests with the purifier or without it, showing an IR difference of 48.5% [CI(15.9-81), p=0.004]. Furthermore, the IR ratio was calculated obtaining a value of 3.3, confirming that RCI diminished more than 3-fold the presence of the SARS-CoV-2 in the air of the patients' rooms, thus laying the first stone in the fight for prevention of SARS-CoV-2 dissemination indoors.

Urban green spaces and childhood leukemia incidence: A population-based case-control study in Madrid

BACKGROUND

Childhood leukemia is the most common childhood cancer. To date, few risk factors related to predisposition have been identified; therefore, new hypotheses should be considered.

OBJECTIVE

To explore the possible relationship of residential proximity to urban green spaces on childhood leukemia.

METHODS

We conducted a population-based case control study in the metropolitan area of Madrid from 2000 to 2015. It included 383 incident cases and 1935 controls, individually matched by birth year, sex and area of residence. Using the geographical coordinates of the participants' home residences, we built a proxy for exposure with four distances (250 m, 500 m, 750 m and 1 km) to urban parks (UPs) and urban wooded areas (UWAs). We employed logistic regression models to determinate the effect of them on childhood leukemia adjusting for environmental and socio-demographic covariates.

RESULTS

we found a reduction in childhood leukemia incidence at a distance of 250 m from UPs (OR = 0.78; 95%CI = 0.62-0.98), as well as a reduction of the incidence in the Q3 and Q4 quintiles for exposure to UWAs, in the 250 m and 500 m buffers respectively (Q3 (250 m): OR = 0.69; 95%CI = 0.48-1.00; and, Q4 (500 m): OR = 0.69; 95%CI = 0.48-0.99).

CONCLUSIONS

Our results suggest a possible association between lower incidence of childhood leukemia and proximity to different forms of urban green space. This study is a first approach to the possible urban green space effects on childhood leukemia so is necessary to continue studying this spaces taking into account more individual data and other environmental risk factors.

Environment, lifestyle behavior and health-related quality of life in childhood and adolescent cancer survivors of extracranial malignancies

BACKGROUND

Childhood cancer is a chronic disease with high survival rates. Childhood cancer survivors (CCS) can still face health effects later in their lives. Health-related quality of life (HRQoL) and the factors that modify it allow CCS and their families to improve care in the long-term follow-up. This study aims to: (1) examine the differences in HRQoL between CCS of extracranial malignancies and a comparison group, and (2) explore the clinical, environmental and lifestyles factors implicated in the HRQoL of CCS.

METHODS

In this cross-sectional study with a case vs. non-case comparison, the HRQoL of 117 CCS between 8 and 18 years old was compared with healthy non-cases paired by sex and age. The Pediatric Environmental History (PEHis) was applied to obtain information on sociodemographic, clinical, environmental and lifestyle factors. The PedsQL™ Generic Core Scales questionnaire was used to evaluate HRQoL.

RESULTS

In the multivariate analysis among the CCS, the following variables were significantly associated with HRQoL: Poor outdoor air quality (Total, Psychosocial, Emotional, Social and School domains); household income (Total, Psychosocial and School domains); and the presence of late effects (Total, Physical, Psychosocial, and Social domains); regular contact with nature (Physical domain); and the daily hours of screen-time (Emotional domain). CCS present HRQoL results superior to the non-cases group in the physical domain (86.10 vs. 80.34; p=0.001), finding no differences in the other domains evaluated.

CONCLUSIONS

An environmental and community health approach, such as PEHis, in CCS long-term programs promoting the creation of healthier environments and lifestyles contributes to improving their HRQoL and secondarily other chronic diseases.

Social distancing at health care centers early in the pandemic helps to protect population from COVID-19

The impact of COVID-19 outbreak has been unequal across Spanish regions. The epidemic wave has been smoother in the Region of Murcia (RM) (6 deaths/100,000 residents). Physical distance from health centers from day 0 is an additional social distancing measure that confers an advantageous starting position in the fight against COVID-19. Late healthcare distancing measures are not as powerful as the early ones.

Secondhand smoke: A new and modifiable prognostic factor in childhood acute lymphoblastic leukemias

BACKGROUND

The 5-year overall survival (OS) in childhood acute lymphoblastic leukemia (ALL) has reached 90% in high-income countries, levels that can no be longer overcome with strategies based on intensification of treatment. Other approaches in the search for new and modifiable prognostic factors are necessary to continue to improve these rates. The importance of environmental factors in the etiopathogenesis of childhood ALL has been regaining interest but its role in the prognosis and survival of this disease is not well explored. We aim to investigate the association between secondhand smoke (SHS) and survival in children diagnosed with ALL.

METHODS

We analyzed survival rates in 146 patients under the age of 15 years diagnosed with ALL between January 1998 and May 2016 in the Region of Murcia, Spain. Evaluation of parental SHS and other known prognostic factors (sex, age, white blood cell count at diagnosis, cytogenetics, NCI/Rome Criteria, early response to therapy, and relapse) were assessed for impact on OS, event-free survival (EFS), cumulative incidence of relapse (CIR), and treatment-related mortality (CITRM) using Kaplan-Meier analysis, Cox regression, and Fine-Gray model.

RESULTS

The mean follow-up time was 105.3 months (±66.5). Prenatal exposure to SHS due to parental smoking was highly prevalent. Of the mothers, 44.4% and 55.5% of the fathers smoked at some point during pregnancy. After the child's diagnosis of ALL 39.7% of mothers and 45.9% of fathers reported smoking. The Cox proportional hazards model showed that maternal smoking during pregnancy and after diagnosis (HR = 4.396, 95% CI: 1.173-16.474, p = 0.028); and relapse (HR = 7.919; 95% CI: 2.683-21.868; p < 0.001) are independent prognostic factors in determining survival. The Fine-Gray model showed that maternal smoking during pregnancy and after diagnosis (HR = 14.525, 95% CI: 4.228-49.90, p < 0.001) is an independent prognostic factor in CITRM.

CONCLUSIONS

Persistent SHS worsens OS and TRM in children with ALL. This negative impact contributes to a different prognosis and may possibly provide an exceptional insight into new therapeutic approaches, including environmental aspects such as prevention and smoking cessation to improve survival outcomes.

Spatial clustering of childhood leukaemia with the integration of the Paediatric Environmental History

BACKGROUND

Leukaemia remains the most common type of paediatric cancer and its aetiology remains unknown, but considered to be multifactorial. It is suggested that the initiation in utero by relevant exposures and/or inherited genetic variants and, other promotional postnatal exposures are probably required to develop leukaemia. This study aimed to map the incidence and analyse possible clusters in the geographical distribution of childhood acute leukaemia during the critical periods and to evaluate the factors that may be involved in the aetiology by conducting community and individual risk assessments.

MATERIALS AND METHODS

We analysed all incident cases of acute childhood leukaemia (<15 years) diagnosed in a Spanish region during the period 1998-2013. At diagnosis, the addresses during pregnancy, early childhood and diagnosis were collected and codified to analyse the spatial distribution of acute leukaemia. Scan statistical test methodology was used for the identification of high-incidence spatial clusters. Once identified, individual and community risk assessments were conducted using the Paediatric Environmental History.

RESULTS

A total of 158 cases of acute leukaemia were analysed. The crude rate for the period was 42.7 cases per million children. Among subtypes, acute lymphoblastic leukaemia had the highest incidence (31.9 per million children). A spatial cluster of acute lymphoblastic leukaemia was detected using the pregnancy address (p<0.05). The most common environmental risk factors related with the aetiology of acute lymphoblastic leukaemia, identified by the Paediatric Environmental History were: prenatal exposure to tobacco (75%) and alcohol (50%); residential and community exposure to pesticides (62.5%); prenatal or neonatal ionizing radiation (42.8%); and parental workplace exposure (37.5%) CONCLUSIONS: Our study suggests that environmental exposures in utero may be important in the development of childhood leukaemia. Due to the presence of high-incidence clusters using pregnancy address, it is necessary to introduce this address into the childhood cancer registers. The Paediatric Environmental History which includes pregnancy address and a careful and comprehensive evaluation of the environmental exposures will allow us to build the knowledge of the causes of childhood leukaemia.

Childhood cancer in small geographical areas and proximity to air-polluting industries

AIM

Pediatric cancer has been associated with exposure to certain environmental carcinogens. The purpose of this work is to analyse the relationship between environmental pollution and pediatric cancer risk.

METHOD

We analysed all incidences of pediatric cancer (<15) diagnosed in a Spanish region during the period 1998-2015. The place of residence of each patient and the exact geographical coordinates of main industrial facilities was codified in order to analyse the spatial distribution of cases of cancer in relation to industrial areas. Focal tests and focused Scan methodology were used for the identification of high-incidence-rate spatial clusters around the main industrial pollution foci.

RESULTS

The crude rate for the period was 148.0 cases per 1,000,0000 children. The incidence of pediatric cancer increased significantly along the period of study. With respect to spatial distribution, results showed significant high incidence around some industrial pollution foci group and the Scan methodology identify spatial clustering. We observe a global major incidence of non Hodgkin lymphomas (NHL) considering all foci, and high incidence of Sympathetic Nervous System Tumour (SNST) around Energy and Electric and organic and inorganic chemical industries foci group. In the analysis foci to foci, the focused Scan test identifies several significant spatial clusters. Particularly, three significant clusters were identified: the first of SNST was around energy-generating chemical industries (2 cases versus the expected 0.26), another of NHL was around residue-valorisation plants (5 cases versus the expected 0.91) and finally one cluster of Hodgkin lymphoma around building materials (3 cases versus the expected 2.2) CONCLUSION: Results suggest a possible association between proximity to certain industries and pediatric cancer risk. More evidences are necessary before establishing the relationship between industrial pollution and pediatric cancer incidence.

[Analysis of small areas of pediatric cancer in the municipality of Murcia (Spain)]

INTRODUCTION

Occasionally, primary care pediatricians notice the presence of small clusters of pediatric cancer (PC), but are often frustrated by the findings after statistical analysis. The study of small areas in spatial epidemiology has led to advances in identifying clusters and the environmental risk factors involved. The purpose of this study was to describe the PC incidence and the spatial distribution at the minimum level of disaggregation possible in Murcia, presenting the first urban municipality map of PC in Spain.

MATERIALS AND METHODS

A population-based descriptive study was conducted on the PC cases diagnosed in children younger than 15 years, between 1998 and 2013 in the municipality of Murcia. Cases were classified by sex, age group, and tumor type. Coordinates of home addresses at the time of diagnosis were assigned to each case, and spatial and spatio-temporal analyses were carried out at the level of census tracts, using FleXScan and SatScan.

RESULTS

A total of 155 cases of PC were diagnosed during this period. The overall incidence of PC (138/10(6) of children under the age of 15) and the incidence for individual tumor types were within the expected ranges for Europe. A spatio-temporal cluster of Hodgkin lymphoma was identified.

CONCLUSIONS

Small area analysis of PC cases may be a useful tool for the identification of PC clusters, which would allow for the generation of hypotheses regarding disease etiology, as well as developing urban models for environmental surveillance of PC.

[The association of adherence to a Mediterranean diet during early pregnancy and the risk of gastroschisis in the offspring]

OBJECTIVES

The aim of this study was to study the association of adherence to the Mediterranean diet in early pregnancy maternal and the offspring's risk of gastroschisis.

METHODS

Case-control study. We describe 11 cases of gastroschisis in the region of Murcia from 2007 to 2012 and 34 concurrent controls. At the time of diagnosis each of the cases completed a validated Food Frequency Questionnaire (FFQ) consisting of 98 items on the periconceptional diet. Confounding factors: smoking, exposure to cannabis / marihuana, age of the parents, BMI, income and educational level. We conducted a descriptive and multivariate logistic regression statistical analysis.

RESULTS

Mothers of children with gastroschisis were younger (20.8 years, 95% CI 17.3 to 24.2) and their diet consisted of less caloric intake, saturated fat and monounsaturated fats and proteins than controls. The Odds Ratio (OR) in the multivariate model controlling for confounding factors: maternal age (year) 0.70 (95% CI 0.51 to 0.96), monounsaturated fatty acids (oleic acid, g) 0.79 (95% CI 0.65 to 0, 97) and vegetable intake (rations/week) 0.70 (95% CI 0.48 to 1.00).

CONCLUSION

A maternal diet rich in oleic acid and vegetable products may prevent vascular risk of onphalomesenteric arteries reducing the risk of gastroschisis.

Congenital fibrosarcoma and history of prenatal exposure to petroleum derivatives

Congenital fibrosarcoma (CFS) is a rare fibrous tissue malignancy that usually presents in the first few years of life. It is unique among human sarcomas in that it has an excellent prognosis. We describe a temporal clustering of a number of cases of CFS and investigate the possible associated prenatal risk factors. The Pediatric Environmental History, a questionnaire developed in our clinic that is instrumental in determining environmental risk factors for tumor-related disease, was essential in documenting the presence or absence of risk factors considered as human carcinogens. We found a history of exposure to petroleum products in four cases of CFS that occurred at a greater than expected rate in a short time frame-an apparent cancer cluster. We call attention to the possibility that exposure to petroleum products raises the risk of developing CFS. While future studies should focus on systematic investigation of CFS and its underlying mechanisms, this report suggests the need for proactive measures to avoid exposure to solvents and petroleum products during pregnancy.

Head circumference at birth and exposure to tobacco, alcohol and illegal drugs during early pregnancy

AIMS

We aimed to assess the effects of exposure to tobacco smoke, alcohol and illegal drugs during early pregnancy on the head circumference (HC) at birth of otherwise healthy neonates.

METHODS

A follow-up study from the first trimester of pregnancy to birth was carried out in 419 neonates. An environmental reproductive health form was used to record data of substance exposure obtained during the first obstetric visit at the end of the first trimester. A multiple linear regression model was created for this purpose.

RESULTS

Alcohol intake during pregnancy and medical ionizing radiation exposure were the most significant predictors of HC. The mothers' alcohol consumption increased with the mothers' and fathers' education level, net family income and fathers' alcohol consumption. In contrast, maternal smoking decreased with increasing mothers' and fathers' education level and net family income. About 13% of the surveyed embryos were exposed to illegal drugs.

CONCLUSIONS

Mild to moderate alcohol consumption diminishes the at-birth HC of theoretically healthy newborns in a linear form. There was no threshold dose. We perceived a need for increasing the awareness, and for training, of health care professionals and parents, in regard to risks of alcohol consumption and for recommending abstinence of these substances in both parents during pregnancy. It should also be remembered that medical ionizing radiation should be performed only during the first half of the cycle in fertile women. We think that our study has an important social impact as it affords data for implementing policies for promoting "healthy pregnancies".

Space-time clustering in childhood nervous system tumors in the Region of Murcia, Spain, 1998-2009

AIMS

The aims of this study are the following: first, to analyze incidence, trends, and survival of nervous system tumors in children under the age of 15 in the Region of Murcia, Spain, during the years 1998-2009 and second, to evaluate if certain environmental exposures may be involved in the etiology of childhood nervous system tumors. The study was performed on the spatial and temporo-spatial distribution of the observed cases.

METHODS

The Environment and Pediatric Cancer in the Region of Murcia is an ongoing research project aimed at carefully collecting pediatric environmental history (PEH) and to use geographical information systems to map the incidence and to analyze the geographical distribution of pediatric cancer incidence in our region. Between 1998 and 2009, 125 patients were diagnosed with nervous system tumors. The spatial and temporal space clusters were evaluated using Kulldorff's statistics. Address at diagnosis was the main feature evaluated.

RESULTS

The incidence (cases/million children) for central nervous system (CNS) tumors was 34.2, that for sympathetic nervous system tumors was 10.9, and that for retinoblastoma was 1.9. There was evidence of space clustering for medulloblastoma and space-time clustering for all tumors, CNS tumors, astrocytoma, and neuroblastoma.

CONCLUSIONS

The incidence and survival for each type and subtype of nervous system tumors were within the reported values for the European region. There is evidence that spatial and spatial-temporal distribution in these cases is not random. The development of a careful PEH in these patients will help to reinforce geographical information system studies and to ascertain the importance of associated risk factors.

[Non dietetic environmental risk factors in prostate cancer]

INTRODUCTION

The aim is to update and disclose the main environmental risk factors, excluding dietary factors, involved in the etiopathology of prostate cancer.

MATERIALS AND METHOD

Bibliographic review of the last 25 years of non-dietary environmental risk factors associated with prostate cancer between 1985 and 2010, obtained from MedLine, CancerLit, Science Citation Index and Embase. The search profiles were Environmental Risk Factors/Tobacco/Infectious-Inflammatory Factors/Pesticides/Vasectomy/Occupational Exposures/Chemoprevention Agents/Radiation and Prostate Cancer.

RESULTS

While some non-dietary environmental risk factors increase the risk of acquiring the disease, others decrease it. Of the former, it is worth mentioning exposal to tobacco smoke, chronic infectious-inflammatory prostatic processes and occupational exposure to cadmium, herbicides and pesticides. The first factors that reduce the risk are the use of chemopreventive drugs (Finasterida, Dutasteride) and exposure to ultraviolet solar radiation. With the current data, a vasectomy does not influence the risk of developing the disease.

CONCLUSIONS

The slow process of prostate carcinogenesis is the final result of the interaction of constitutional risk and environmental factors. Non-dietary environmental factors play an important role in the etiopathology of this disease. To appropriately assess the risk factors, extensive case studies that include all the possible variables must be analysed.

[Constitutional risk factors in prostate cancer]

INTRODUCTION

The aim of this review is to update and divulge the main constitutional risk factors involved in the etiopathology of prostate cancer.

MATERIALS AND METHODS

Bibliographic review of the scientific literature on the constitutional risk factors associated with prostate cancer between 1985 and 2010, obtained from MedLine, CancerLit, Science Citation Index and Embase. The search profiles were Risk Factors, Genetic Factors, Genetic Polymorphisms, Genomics, Etiology, Epidemiology, Hormonal Factors, Endocrinology, Primary Prevention and Prostate Cancer.

RESULTS

The principal constitutional risk factors are: age (before the age of 50 years at least 0.7% of these neoplasms are diagnosed and between 75-85% are diagnosed after the age of 65 years), ethnic-racial and geographic (African Americans present the highest incidence rates, and the lowest are found in South East Asia), genetic, family and hereditary (family syndromes cover 13-26% of all prostate cancers, of which 5% are of autosomal dominant inheritance), hormonal (it is a hormone-dependent tumour), anthropometric (obesity increases the risk), perinatal, arterial hypertension and type 2 diabetes.

CONCLUSIONS

Constitutional risk factors play a very important role in the etiopathology of prostate cancer, especially age, ethnic-racial-geographic factors and genetic-family factors. We cannot know what percentage of these neoplasms are a result of constitutional factors, because our knowledge of these factors is currently lacking.

[Environment and paediatric cancer in the Region of Murcia (Spain): integrating clinical and environmental history in a geographic information system]

INTRODUCTION

Environment and Paediatric Cancer (PC) in the Region of Murcia (RM) is an on-going research project that has the following aims: to collect a careful paediatric environmental history (PEH) and to use geographical information systems (GIS) to map the incidence and analyze the geographic distribution of the PC incidence in the RM. The objectives are to present the methodology used for the collection and processing of data and disseminate initial results on the spatial and temporal incidence of PC in the RM (Spain).

MATERIAL AND METHODS

A descriptive and georeference study of all PC cases under 15 years, diagnosed from 1 January 1998 to December 31, 2009. Three postal addresses were assigned to each case, residence during pregnancy, postnatal, and at the time of diagnosis. Other variables such as sex, date of birth, date of diagnosis, and histopathology classification were collected.

RESULTS

No increase was observed in the trend of incidence of PC. The crude annual incidence rate was 14.3 cases per 100,000 children under 15 years. The standardised incidence ratio was higher in the north-west of the RM. Before diagnosis, 30% of cases had a different postal address than during the pregnancy.

CONCLUSIONS

Integrating the spatial and temporal information through the PEH in a GIS should allow the identification and study of space-time clusters through an environmental monitoring system in order to know the importance of associated risk factors.

Transgenerational tobacco smoke exposure and childhood cancer: an observational study

AIM

Although tobacco smoke is an established risk factor for adult cancer, studies of the association between parental smoking and childhood cancer have produced inconsistent results. To investigate the transgenerational relationship between pre-natal and post-natal tobacco smoke exposure from the grandmother's pregnancies until after the post-natal period and childhood cancer.

METHODS

Exposure to tobacco smoke was recorded for three generations. Data were collected through personal interviews using the paediatric environmental history, and were compared among 128 children with cancer and 128 matched controls. The contingency tables and a logistic multivariable regression model were used to control for possible confounding factors.

RESULTS

Smoke exposure during oogenesis (maternal grandmother smokers)--odds ratio (OR) 2.2 (95% confidence interval (CI) 1.1-4.9)--and during the mother' pregnancies--OR 1.8 (95% CI 1.1-3.3)--were significantly associated with an increased risk of childhood cancer.

CONCLUSIONS

Tobacco smoke exposure during the grandmother's and mother's pregnancies increase the risk of cancer in the descendants. The results suggest that the biological plausibility of the association between parental smoking and paediatric cancer can be explained by the large latency period of paediatric carcinogenesis.

Full breastfeeding and paediatric cancer

AIM

It has been suggested that there is an inverse association between breastfeeding and the risk of childhood cancer. We investigated the association between full breastfeeding and paediatric cancer (PC) in a case control study in Spain.

METHODS

Maternal reports of full breastfeeding, collected through personal interviews using the Paediatric Environmental History, were compared among 187 children 6 months of age or older who had PC and 187 age-matched control siblings.

RESULTS

The mean duration of full breastfeeding for cases were 8.43 and 11.25 weeks for controls. Cases had been significantly more often bottle-fed than controls (odds ratio (OR) 1.8; 95% confidence interval (CI) 1.1-2.8). Cases were significantly less breastfed for at least 2 months (OR 0.5; 95% CI 0.3-0.8), for at least 4 months (OR 0.5; 95% CI 0.3-0.8), and for 24 weeks or more (OR 0.5; 95% CI 0.2-0.9).

CONCLUSIONS

Breastfeeding was inversely associated with PC, the protection increasing with the duration of full breastfeeding. Additional research on possible mechanisms of this association may be warranted. Meanwhile, breastfeeding should be encouraged among mothers.