Examining the Link between Air Quality and Birth Defects in Guanajuato: An Ecological Study Revealing Time Trends

Abstract

Aim: The objective was to determine a correlation between monitored airborne particulate matter and birth defect rates in newborns in the state of Guanajuato, central Mexico. Study Design: An ecological study of time trends was designed. Place and Duration of the Study: Between 2020 and 2023, using databases from monitoring stations and the newborn database in the state of Guanajuato. Methodology: We used information from datasets from 2020 to 2023 and calculated the mean daily for each year of contaminants particles (the monitored particles were PM2.5, PM10, SO2, NO2, CO, and O3), and the Rate of malformations /1000 newborns for each year. Pearson's r and a linear relationship equation were calculated between particulate matter and the birth defect rate per 1,000 live births. Defects were classified either as general or by apparatus and system. Results: Congenital malformations increased in 2023 compared to the previous years (2020-2022). And by apparatus and systems, they increased in the same year for gastrointestinal, genitourinary, musculoskeletal, cardiovascular, ear, nose and throat. Positive correlations were found between PM2.5 and gastrointestinal, genitourinary, musculoskeletal, cardiovascular, and endocrine malformations. Positive correlations were also found with PM10 with malformations by tracts or systems: gastrointestinal, genitourinary, musculoskeletal, cardiovascular, ear, nose, throat, and eye. Positive correlations of SO2 levels were found with neurological, cutaneous, respiratory, and endocrine congenital malformations. For NO2 there were positive correlations for neurological, musculoskeletal, and cutaneous congenital malformations. For CO, neurological, chromosomal, and cutaneous malformations showed positive correlations. For O3, genitourinary and endocrine malformations showed positive correlations. Conclusion: It is concluded that measurements of air quality and congenital malformations should be analyzed with caution, due to several factors, such as the presence of monitoring stations in eight of the 46 municipalities in the state of Guanajuato; another factor that biases the results is the fact that the congenital malformations included in the analysis were those detected at birth; many malformations manifest months after birth.