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ABSTRACT: Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental contaminants that are known to induce oxidative stress. There have been several reports about the link between PAH exposure and complications in pregnancy. This cross-sectional study was conducted to: (1) measure the levels of benzo(a)anthracene (BaA), chrysene (Ch), benzo(b)fluoranthene (BbF), benzo(a)pyrene (BaP), and dibenzo(a,h)anthracene (DBahA) in placentas and maternal and -umbilical cord blood obtained at delivery from 1578 women between June 2005 and 2006 in the area of Al-Kharj, Saudi Arabia; (2) assess their influence on various anthropometric measures of birth outcome taking into consideration the carcinogenic properties of these PAHs; and (3) determine the degree of PAH-related oxidative DNA damage and birth outcome. Among the five tested PAHs, only BaP was carcinogenic; therefore, the levels of the other four probable or possible carcinogenic PAHs (BaA, Ch, BaF, and DBahA) were summed as ∑4-PAHs. Levels of 1-hydroxypyrene (1-HP) were determined in maternal urine samples as a biomarker of PAH internal dose. Urinary cotinine (COT) was measured as an index of smoking. The following markers of oxidative stress were selected: malondialdehyde (MDA) in cord (C-MDA) and maternal (M-MDA) serum and 8-hydroxy-2-deoxyguanosine (8-OHdG) in maternal urine. None of the tested PAHs was found in maternal or cord blood. However, all five PAH compounds were detected in placentas; Ch was the highest (6.582μg/kg dry wt.), and BaA was the lowest (0.236μg/kg dry wt.). The mean concentration of urinary 1-HP found in this study was 0.216±0.856μg/g Cr. After adjusting for gestational age and other confounding variables, regression models revealed an inverse relationship between placental weight, cord length and placental BaP. A similar trend was observed between cord length and ∑4-PAHs in placental tissues. Urinary 1-HP, though, cannot be used as an unequivocal biomarker of PAH exposure, but it can be an appropriate indicator of exposure to environmental tobacco smoke (ETS). The data demonstrate that ETS exposure (as measured by urinary COT) may adversely affect birth outcome as shown by reduced head circumference, birth weight, and birth length, as well as increased cephalization index. The positive relationship between 8-OHdG levels and 1-HP in urine provides evidence of an oxidative stress mechanism. Although this study provides no direct evidence of an association between PAH exposure and DNA damage, increased oxidative stress in the form of lipid peroxidation significantly affected various birth measures. Therefore, there is a need for studies regarding PAH exposure and its associated biological effects to determine the extent of potential fetal damage as well as possible long-term effects, such as cancer.
Science of The Total Environment 01/2013; 444C:565-578. · 3.29 Impact Factor
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ABSTRACT: Lead, cadmium and mercury were measured in placental tissue, umbilical cord and maternal blood samples of 1578 women who delivered at the Al-Kharj King Khalid Hospital between 2005 and 2006. The aim of this study was to evaluate the status of heavy metal exposure in mothers and their newborns and to identify predictors of maternal exposure. Lead was detected in all cord and maternal blood and in 96% of placental tissues. Only in 0.89% and 0.83% of cord and maternal blood samples were the levels of lead above the CDC threshold limit of 10 μg/dl. Maternal blood lead was also higher (2.3%) than the German Reference value in women of 7 μg/dl. Approximately 9.3% of women had a placental lead above the 95th percentile in the range of 0.83-78 μg/g dry wt., a level of possible developmental toxicity. Cadmium was detected in 94.8% and 97.9% of cord and maternal blood samples respectively, though only five newborns had a cadmium level above the OSHA threshold limit of 5 μg/l. Comparing our results to the newly revised German Reference value for nonsmokers, 48.6% of mothers had blood cadmium levels >1.0 μg/l. We found as well that 25% of women had placental cadmium in the >75th percentile, in the range of 0.048-4.36 μg/g dry wt., which is likely to affect fetal growth and development. Of the maternal and cord blood samples, 11.2% and 13%, respectively, had mercury levels >5.8 μg/l, which is the EPA reference dose. Nearly 49% of women had mercury levels >2.0 μg/l, the German Reference value for those who consume fish ≤3 times a month. Around 50% of the mothers had placental mercury in the range of 0.031-13.0 μg/g dry wt. Regression analyses indicated that the levels of metals in the blood and placenta were influenced by several factors. This study provides informative baseline biomonitoring data and reveals a substantial exposure to heavy metals in non-occupationally exposed Saudi mothers and their newborns that might jeopardize the health of both. Additional research is also urgently needed to explore factors such as environment, diet, lifestyle and/or cultural habits contributing to maternal and fetal exposures. Preventive measures to eliminate or minimize the unnecessary risk of fetus exposure to heavy metals or other pollutants during pregnancy should be initiated once these factors are identified.
International journal of hygiene and environmental health 11/2010; 214(2):79-101. · 2.64 Impact Factor
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ABSTRACT: Although p,p'-dichlorodiphenyltrichloroethane (DDT) is banned for agricultural purpose in Saudi Arabia, it is occasionally used to control vector-borne diseases in certain regions of the country.
A case-control study was designed to investigate the possible effects of DDT and its metabolites on pregnancy and fertilization rate outcome. The study population was composed of 619 Saudi women (age 19-50 years) who sought in-vitro fertilization (IVF) treatment between 2002 and 2003.
p,p'-DDE, the main metabolite of DDT, was the most frequently detected residue in serum or follicular fluid, with mean values of 1.646 microg/L and 0.407 microg/L, respectively. After controlling for many potential confounding variables, multiple logistic regression analysis revealed no association between pregnancy outcome or fertilization rate and p,p'-DDE levels in serum or follicular fluid.
The inability to identify an effect may be related to the comparatively low concentrations of DDE in our population. But because p,p'-DDE was detected in the serum of 77.7% our participants, it should be considered as a matter of public heath concern. Currently there is no active source of DDT in our region; therefore, further studies are needed to identify sources in order to develop preventive measures because we can not exclude its potential reproductive toxicity.
Medical science monitor: international medical journal of experimental and clinical research 11/2009; 15(11):BR320-33. · 1.70 Impact Factor
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ABSTRACT: The goal of this study was to assess the effect of prenatal and postnatal lead exposure on early cognitive development of infants using the Bayley Scale of Infant Development (BSID-I) at the age of 6, 12, 18, and 24 months in a longitudinal study. Based on the results of 653 cord blood lead levels, infants were classified into three groups for neuropsychological assessments: low lead risk (<10th percentile) and high lead risk (>10th percentile) of the distribution of cord blood lead level were designated as low (< or = 1.045 microg/dL) and high (> or = 3.466 microg/dL) lead risk groups. Blood lead levels in between the <10th and >90th percentile were designated as mid lead risk group. A total of 66 infants were supposed to be selected from each group for a follow-up study. Of these, only 106 participated 6 months after the study. During the follow-up study, the dropout was very high with attrition rates of 74.5%, 52.8%, and 39.6% during the 12, 18, and 24 months. Mean blood lead levels increased from 3.36 to 4.45 microg/dL between the ages of 6 and 24 months, but the standardized Mental Development Index (MDI) and Psychomotor Development Index (PDI) decreased from 99.26 and 98.13 (6 months old) to 93.29 and 82.52, respectively (24 months old). Due to the high rate of attrition, most of the infants in the low group were lost. Therefore, we used the 75th percentile of blood lead levels as a cutoff in the statistical analyses. After adjustment for a large number of confounding variables, prenatal lead exposure was found to be significantly associated with the standardized MDI and PDI scores at the age of 6 months old with a P value of 0.02 for both. A borderline significant effect of prenatal lead exposure was also seen on standardized PDI scores at the age of 24 months (P = 0.09). On the other hand, no relationship was seen between postnatal blood lead levels and concurrent cognitive development scores. Such an observation is not conclusive because of low statistical power due to small sample size. Our results provide additional evidence for low prenatal lead exposure effects on cognitive development in Saudi infants living in a rural area.
Journal of environmental pathology, toxicology and oncology : official organ of the International Society for Environmental Toxicology and Cancer. 01/2009; 28(4):283-302.
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ABSTRACT: This study examined the chemopreventive effect of Nigella sativa and some of its antioxidant constituents on a number of colon cancer biomarkers in rats induced with azoxymethane (AOM). Sixty male Sprague-Dawley rats were randomly assigned into ten subgroups: vehicle (1-5) and experimental (6-10). The rats in each group were fed one of the following diets: basal diet, (200 mg/kg) Nigella sativa, (0.2 mg/kg) selenium, (1.2 mg/kg) all-trans-retinol plus (100 mg/kg) DL-alpha-tocopherol and (10 mg/kg) thymoquinone, respectively. Only rats in subgroups 6-10 were injected with AOM (15 mg/kg) once per week for 2 weeks. Both groups were fed their respective diets for 5 weeks. Then they were killed and examined for colonic aberrant crypt foci (ACF). Our result showed that only vitamin supplementation was effective on ACF. Nigella sativa revealed inhibitory effects only on DNA damage (day 34) in the AOM-treated rat group. Alternatively, selenium, thymoquinone and vitamins inhibited the MDA content in the liver. Although the exact mechanisms involved in the protective role of Nigella sativa against the initiation of colon carcinogenesis are not clearly understood, the results suggest that its inhibitory effects might depend on the combined competitive inhibition of various antioxidant constituents of this plant.
Phytotherapy Research 07/2008; 22(10):1311-23. · 2.09 Impact Factor
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ABSTRACT: Extensive data shows a direct link between low-level lead exposure during early development and deficits in neurobehavioral-cognitive performance evident late in childhood through adolescence. Our previous studies confirmed the transfer of lead from the mother to the fetus as well as the effect of low lead exposure on neuropsychological behavior in school children. Such results led us to design a longitudinal survey to evaluate the effect of prenatal and/or postnatal lead exposure on early cognitive development among selected group of children from birth to 2 years of age. During the first stage of this study (between March and July 2004), we measured lead levels in 653 umbilical cord blood samples taken from healthy Saudi mothers delivering at King Khalid Hospital, Al-Kharj. This gave a good opportunity to look at the prevalence of increased blood lead levels in umbilical cord blood and to identify risk factors for prenatal lead exposure. The mean cord lead levels were 2.21 +/- 1.691 microg/dl in the range of 0.284-17.276 microg/dl. Only 1.23% of the newborns had blood lead levels >10 microg/dl, the Center for Disease Control level of concern. To investigate risk factors affecting cord blood lead levels, only subjects with lead levels above the 75th percentile (2.475 microg/dl) were selected in the multiple regression models. We observed that cord blood lead levels were significantly influenced by maternal age, the location of residence and intake of prenatal supplements. Controlling for newborn's head circumferences confounders, it was found that cord blood lead levels were significantly and negatively associated with newborn's head circumference (beta = -0.158, p = 0.036). The negative association was seen between intake of prenatal supplements and cord blood lead levels emphasizing the role of prenatal supplementations during pregnancy. The significant reductions in newborns, head circumferences due to lead exposure may have serious implications for their future performance and achievement. This study reveals that even at low prenatal lead exposure, all possible measures to inspect lead sources in our environment and reduce lead exposure should be taken.
Journal of Tropical Pediatrics 03/2008; 54(5):300-7. · 1.39 Impact Factor
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ABSTRACT: We investigated the effect of lead, cadmium and mercury exposure on pregnancy and fertilization rate outcome among 619 Saudi women (age 19-50 years) who sought in-vitro fertilization (IVF) treatment between 2002 and 2003. The concentrations of lead, cadmium and mercury were measured in both blood and follicular fluids. At levels well below the current US occupational exposure limit guidelines (40microg/dL) and even less than the current Centers for Disease Control and Prevention level of concern for preventing lead poisoning in children (10microg/dL), blood lead level was negatively associated with fertilization outcome in both adjusted and unadjusted logistic regression models. We found that among various demographic, socioeconomic and environmental factors, fish consumption was positively associated with blood lead levels. These results support the hypothesis that a raised blood lead level affects infertility and intervention to reduce the lead exposure might be needed for women of reproductive age. The present results also revealed unexpected finding - the positive relationship between follicular cadmium levels and fertilization outcome, which points to the necessity for further investigation. Though adverse effect of mercury on pregnancy outcome or fertilization rate was not evident in this study, mercury5.8microg/L (EPA safety limit) was found in the blood and follicular fluid of 18.7% and 8.3% of the women, respectively. Concerns about its possible adverse effects on the physiology of reproduction or fetal development cannot be ruled out. It should be noted that skin-lightening creams and dental amalgam were important contributors to mercury exposure. Such finding is alarming and priority for further studies are, urgently, needed.
International Journal of Hygiene and Environmental Health 01/2008; 211(5-6):560-79. · 3.81 Impact Factor
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ABSTRACT: The association between elevated blood pressure and blood cadmium and mercury levels was examined (2001-2002) in 185 Saudi women previously selected for a case-control study of lead and hypertension risk. Blood pressure was measured twice according to the World Health Organization recommendations. Cadmium and mercury were determined with graphite furnace and hydride system-atomic absorption spectrometry, respectively. Mean blood cadmium concentrations were 0.874 +/- 0.995 microg/L in hypertensive and 0.785 +/- 0.665 microg/L in controls. While blood mercury concentrations for hypertensives and controls were 3.506 +/- 3.617 microg/L and 3.687 +/- 3.186 microg/L, respectively. Participants were classified according to the median of blood cadmium and mercury levels. After adjustment for potentially confounding variables, the final logistic regression analyses revealed that women with blood cadmium > or = 0.627 microg/L were 3.934 times were more likely to be hypertensive than those with blood cadmium levels < 0.627 microg/L, although this was marginally significant (p = 0.098). This was likely the result of the small number of subjects, resulting in the weak power to detect a strong significant difference between hypertensives and control cases. On the other hand, the final regression model showed no association between hypertension and mercury. However, this finding should not be conclusive because of the inappropriate choice of the biomarker indicator. Nevertheless, our study supports the hypothesis that exposure to cadmium might increase the risk of hypertension.
Biological Trace Element Research 07/2006; 112(1):13-29. · 1.92 Impact Factor
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ABSTRACT: Lead, cadmium, and mercury concentrations were determined in breast milk of Saudi lactating mothers from Riyadh and Al-Ehssa regions in Saudi Arabia who were not occupationally exposed. The mean levels for cadmium, lead, and mercury were 1.732 microg/L, 31.671 microg/L, and 3.100 microg/L, respectively. In contrast to mercury, mothers living in the Al-Ehssa region had significantly higher cadmium and lead concentrations in their breast milk than those in the Riyadh region. The estimated weekly intakes of cadmium, lead, and mercury of breast-fed infants in this study were in some cases higher than the Provisional Tolerance Weekly Intake (PTWI) recommended by FAO/WHO, which pose a threat to their health. This necessitates the urgent need to undertake a comprehensive study to determine the sources of exposure to these heavy metals. Breast-feeding is of great beneficial value for the infant's development; therefore, efforts should be made to prevent its contamination with environmental pollutants.
Biological Trace Element Research 02/2003; 96(1-3):21-37. · 1.92 Impact Factor
