Cell Proliferation of umbilical cord blood cells as a sub-clinical endpoint in relation to environmental exposures: biomonitoring pilot study in Southern Israel

Abstract

Background: An adverse effect of air-pollution on cell physiology supposedly involves impairment of cell oxygenation and eventually - of its proliferation process. Aims: We assessed feasibility of using cell proliferation (CP) ratio of lymphocytes in umbilical cord blood as an indicator of a subclinical pathology in fetus which might be sensitive to environmental factors. Methods: We enrolled 210 Arab-Bedouin women giving birth in a local hospital. A questionnaire and cord blood samples were collected. This population is featured by high rates of birth anomalies and multiple environmental exposures, originating from the local industrial park (IP), frequent male smoking and open fire usage. Samples were maintained at +2C and tested by MTT Cell Proliferation Assay within 48 hours. Results: An average CP ratio was 2.4±1.2, Me=2.2, (0.3-6.7). Women in the 1st quartile (Q) of CP ratio were frequently diagnosed with preeclampsia compared with women in the 4th Q (6.0% vs. 0%, pv=0.05), they complained more about noisy neighborhood (14.7% vs. 2.5%, pv=0.04) and reported noise and vibration at their husbands’ work (88.2% vs. 62.5%, pv=0.01; 61.8% vs. 37.5%, pv=0.04, respectively). Women in the 4th Q frequently lived in shacks or tents, used open fire or stove without chimney for heating or cooking (42.5% vs. 29.4% in 1st Q, NS) complained more about nearby transport (45.0% vs. 20.6%, pv=0.03) and smell (20.0% vs. 8.8%, pv=0.13). They were more likely to reside in the direction of a prevailing wind from the local IP (30.0% vs. 11.8%, pv=0.05). CP ratio was higher among newborns with minor anomalies (Me=2.9, n=8) compared to healthy newborns (Me =2.2, n=192). However, CP ratio among newborns with major anomalies was lower than in healthy newborns (Me =1.7, n=10). This disparity might reflect a different pathophysiology for minor and major anomalies. Conclusions: Proliferation of cord blood cells might be considered as an early subclinical indicator, sensitive to environmental exposures and reflective of birth anomalies.