Joanna Jurewicz

Exposure to phthalates: Reproductive outcome and children health. A review of epidemiological studies

Phthalates are a family of industrial chemicals that have been used for a variety of purposes. As the potential consequences of human exposure to phthalates have raised concerns in the general population, they have been studied in susceptible subjects such as pregnant women, infants and children. This article aims at evaluating the impact of exposure to phthalates on reproductive outcomes and children health by reviewing most recent published literature. Epidemiological studies focusing on exposure to phthalates and pregnancy outcome, genital development, semen quality, precocious puberty, thyroid function, respiratory symptoms and neurodevelopment in children for the last ten years were identified by a search of the PubMed, Medline, Ebsco, Agricola and Toxnet literature bases. The results from the presented studies suggest that there are strong and rather consistent indications that phthalates increase the risk of allergy and asthma and have an adverse impact on children’s neurodevelopment reflected by quality of alertness among girls, decreased (less masculine) composite score in boys and attention deficit hyperactivity disorder. Results of few studies demonstrate negative associations between phthalate levels commonly experienced by the public and impaired sperm quality (concentration, morphology, motility). Phthalates negatively impact also on gestational age and head circumference; however, the results of the studies were not consistent. In all the reviewed studies, exposure to phthalates adversely affected the level of reproductive hormones (luteinizing hormone, free testosterone, sex hormone-binding globulin), anogenital distance and thyroid function. The urinary le vels of phthalates were significantly higher in the pubertal gynecomastia group, in serum in girls with premature thelarche and in girls with precocious puberty. Epidemiological studies, in spite of their limitations, suggest that phthalates may affect reproductive outcome and children health. Considering the suggested health effects, more epidemiologic data is urgently needed and, in the meantime, precautionary policies must be implemented.

Prenatal and Childhood Exposure to Pesticides and Neurobehavioral Development: Review of Epidemiological Studies

OBJECTIVES Conventional pesticides comprise a diverse group of substances intended to destroy, repel or control organisms identified as pests. Compared to the studies on lead, mercury, and PCBs, few epidemiological studies have assessed the developmental neurotoxicity of pesticides. MATERIALS AND METHODS Epidemiological studies focused on the neurobehavioural development of children exposed to pesticides were identified by searching the PubMed, Medline, EBSCO, Agricola and TOXNET databases. RESULTS The findings of the studies reviewed imply that childrens exposure to pesticides may bring about impairments in their neurobehavioral development. Children exposed to organophosphate pesticides (OP), both prenatally and during childhood, may have difficulties performing tasks that involve short-term memory, and may show increased reaction time, impaired mental development or pervasive developmental problems. In newborns, the effects of OP exposure are manifested mainly by an increased number of abnormal reflexes, while in adolescents, by mental and emotional problems. The studies investigating association between exposure to organochlorine pesticides and neurodevelopmental effects show inconsistent results. While some studies report impairments in mental and psychomotor functions, other studies do not confirm the above. CONCLUSION The information deriving from epidemiological studies indicate a need to increase awareness among people and children exposed to pesticides about the association between the use of pesticides and neurodevelopmental impairments. Therefore, the principle of prudence should become a rule.

Environmental factors and semen quality.

OBJECTIVES An increasing number of reports suggest that chemical and physical agents in the environment, introduced and spread by human activity, may affect male fertility in humans. This article aims at evaluating the impact of environmental exposures (pesticides, phthalates, PCBs, air pollution, trihalomethanes (THMs), mobile phones) on semen quality, by reviewing most recent published literature. MATERIALS AND METHODS Epidemiological studies focusing on exposure to environmental factors and semen quality for the last ten years were identified by a search of the Pubmed, Medline, Ebsco, Agricola and Toxnet literature bases. RESULTS The results from the presented studies suggest that there are strong and rather consistent indications that some pesticides besides DBCP (e.g. DDT/Dichlorodiphenyldichloroethylene [DDE], ethylenedibromide, organophosphates) affects sperm count. PCBs are detrimental to sperm motility. In case of air pollution, studies suggest a link between ambient air pollutants and various semen characteristics. Additional research is needed to corroborate this association and to establish the causal agents. Results of few studies on subfertile men demonstrate associations between phthalate levels commonly experienced by the public and impaired sperm quality (impact on sperm concentration, morphology, motility), but the findings have not been corroborated in studies of men from the general population. Mobile phones might adversely affect the quality of semen by decreasing mostly motility but also the sperm counts, viability and morphology. In spite of their consistent results, most of the studies are rather small. Association between exposure to THMs and poor semen quality was not observed. CONCLUSIONS Epidemiological studies suggest awareness of environmental factors which may affect semen quality. In case both of well proven and disputable reproductive and developmental hazards, it is necessary to prevent parental exposure to the agents associated with those hazards.

Human urinary phthalate metabolites level and main semen parameters, sperm chromatin structure, sperm aneuploidy and reproductive hormones

The aim of the study was to assess the association of phthalate metabolites levels in urine with semen parameters (sperm concentration, motility, morphology, CASA parameters), sperm chromatin structure, sperm aneuploidy and reproductive hormones. The study population consisted of 269 men who were attending an infertility clinic and had normal semen concentration (20-300mln/ml) or slight oligozoospermia (15-20mln/ml). Participants were interviewed and provided a semen sample. The phthalate metabolites were analysed in the urine using a procedure based on the LC-MS/MS method. Urinary phthalate metabolites levels were significantly associated with a decrease in sperm motility (5OH MEHP, MEHP, MINP), CASA parameters (MBP), testosterone level (MEHP) and an increase sperm DNA damage (MBP) and sperm aneuploidy (MBzP, MBP, MEHP, MEP). In view of the importance of human reproductive health and the widespread usage of phthalates, it is important to further investigate these correlations.

Review of current evidence on the impact of pesticides, polychlorinated biphenyls and selected metals on attention deficit / hyperactivity disorder in children

The aim of this review was to investigate the association between attention deficit / hyperactivity disorder (ADHD) or ADHD-related symptoms and industrial chemicals, such as organophosphates and organochlorine pesticides, polychlorinated biphenyls (PCBs), lead, mercury and manganese. Medline, PubMed and EBSCO searches were performed to identify the studies that analyzed the association of prenatal and postnatal child exposure to such toxicants and ADHD or ADHD-related symptoms. The review is restricted to human studies published in English in peer-reviewed journals since 2000. Most of the presented studies focused on pesticides, PCB and lead. The impact of mercury and manganese was investigated less frequently. The findings indicate that children’s exposure to organophosphate pesticides may cause symptoms consistent with pervasive developmental disorder, ADHD or attention problems. Exposures to organochlorine pesticides and PCBs were associated with ADHD-like behaviors such as alertness, quality of alert response, and cost of attention. The studies provided evidence that blood lead level below 10 μg/dl was associated with ADHD or ADHD-related symptoms. Information on the association between exposure to mercury and neurotoxicity is limited, and requires further confirmation in future research. Two studies indicated that exposure to manganese is related to ADHD; such exposure and its impact on children neurodevelopment need to be further investigated. Future studies should use a prospective design with multiple biological samples collected over time for better assessment of exposure and its critical windows. Additionally, inclusion of potential confounding factors and co-exposures is crucial.

Lifestyle and semen quality: role of modifiable risk factors

Abstract The relationship between exposure to lifestyle factors and adverse effects on human reproductive health is debated in the scientific literature and these controversies have increased public and regulatory attention. The aim of the study was to examine the association between modifiable lifestyle factors and main semen parameters, sperm morphology, and sperm chromatin structure. The study population consisted of 344 men who were attending an infertility clinic for diagnostic purposes with normal semen concentration of 20–300 M/ml or with slight oligozoospermia (semen total concentration of 15–20 M/ml) [WHO 1999]. Participants were interviewed and provided semen samples. The interview included questions about demographics, socio-economic status, medical history, lifestyle factors (consumption of alcohol, tobacco, coffee intake, cell phone and sauna usage), and physical activity. The results of the study suggest that lifestyle factors may affect semen quality. A negative association was found between increased body mass index (BMI) and semen volume (p = 0.03). Leisure time activity was positively associated with sperm concentration (p = 0.04) and coffee drinking with the percentage of motile sperm cells, and the percentage of sperm head and neck abnormalities (p = 0.01, p = 0.05, and p = 0.03, respectively). Drinking red wine 1–3 times per week was negatively related to sperm neck abnormalities (p = 0.01). Additionally, using a cell phone more than 10 years decreased the percentage of motile sperm cells (p = 0.02). Men who wore boxer shorts had a lower percentage of sperm neck abnormalities (p = 0.002) and percentage of sperm with DNA damage (p = 0.02). These findings may have important implications for semen quality and lifestyle.

Exposure to environmental and lifestyle factors and attention-deficit / hyperactivity disorder in children — A review of epidemiological studies

Attention-deficit/hyperactivity disorder (ADHD) is one of the most common neurodevelopmental disorders in children. Although the mechanisms that lead to the development of ADHD remain unclear, genetic and environmental factors have been implicated. These include heavy metals and chemical exposures, nutritional and lifestyle/psychosocial factors. The aim of this review was to investigate the association between ADHD or ADHD-related symptoms and widespread environmental factors such as phthalates, bisphenol A (BPA), tobacco smoke, polycyclic aromatic hydrocarbons (PAHs), polyfluoroalkyl chemicals (PFCs) and alcohol. Medline, PubMed and Ebsco search was performed to identify the studies which analyze the association of prenatal and postnatal child exposure to environmental toxicants and lifestyle factors and ADHD or ADHD-related symptoms. The review is restricted to human studies published since 2000 in English in peer reviewed journals. Despite much research has been done on the association between environmental risk factors and ADHD or ADHD symptoms, results are not consistent. Most studies in this field, focused on exposure to tobacco smoke, found an association between that exposure and ADHD and ADHD symptoms. On the other hand, the impact of phthalates, BPA, PFCs, PAHs and alcohol is less frequently investigated and does not allow a firm conclusion regarding the association with the outcomes of interest.

Adverse health effects of children's exposure to pesticides: what do we really know and what can be done about it.

Children may be exposed to pesticides in several ways, such as by transplacental transfer during foetal life, by intake of contaminated breast milk and other nutrients, or by contact with contaminated subjects and areas in the environment such as pets treated with insecticides, house dust, carpets and chemically treated lawns and gardens. Exposure early in life, and particularly during periods of rapid development, such as during foetal life and infancy, may have severe effects on child health and development by elevating the risk of congenital malformations, cancer, malabsorption, immunological dysfunction, endocrine disease, and neurobehavioural deficiencies. As pesticides can also interfere with parental reproductive health, exposure of parents may have consequences for the offspring leading to reduced chance of male birth and increased risk of childhood cancer.

Smoking and alcohol drinking during pregnancy as the risk factors for poor child neurodevelopment – A review of epidemiological studies.

Maternal active and passive smoking and low or moderate alcohol drinking during pregnancy, taking into account the level of exposure and developmental or behavioral outcomes, are recognized as a significant issue from both a clinical and a public health perspective. The article aims at evaluating the impact of prenatal exposure to tobacco smoke constituents and low or moderate alcohol drinking during pregnancy on children neurodevelopment by reviewing the most recently published literature. Relevant studies were identified by searching the Pubmed, Medline and Ebsco literature databases. This review is restricted to 29 human studies published in English in peer reviewed journals since 2006. The studies published recently continued to show some relationship between tobacco smoke exposure, from active and passive maternal smoking during pregnancy, and childrens psychomotor development independent of other variables, but this relationship is not straightforward. The association is mostly consistent for measures of academic achievements and behavioral problems which require further attention. The results of the studies on low or moderate exposure to alcohol are not fully conclusive, but some of them suggest that consumption of alcohol during pregnancy may adversely affect childrens intelligence quotient (IQ), mental health, memory and verbal or visual performance. As the reviewed studies indicate, maternal lifestyle during pregnancy like alcohol drinking or smoking may affect children neurodevelopment. All effort should be taken to eliminate such exposure to ensure appropriate childrens development.

Exposure to widespread environmental toxicants and children’s cognitive development and behavioral problems

Nowadays a special attention is focused on prenatal and childhood exposures to a variety of contaminants in the environment, especially toxicants widely present in the environment and their impact on children’s health and neurodevelopment. This article aims at evaluating the impact of exposure to several widespread toxicants including: polycyclic aromatic hydrocarbons (PAHs), phthalates, bisphenol A, brominated flame retardants and gas cooking on children’s cognitive development and behavioral problems by reviewing most recent published literature. Epidemiological studies focusing on exposure to widespread toxicants and children’s development for the last eleven years were identified by a search of the PubMed, Medline, Ebsco and Toxnet literature bases. The combination of following key words was used: 1) referring to the exposure: pregnancy, prenatal exposure, postnatal exposure, gas cooking, exposure to phthalates, bisphenol A, brominated flame retardants, PAHs and 2) referring to outcome: neurodevelopment, neurobehavior, psychomotor development, behavioral problems, cognitive development, mental health, school achievements, learning abilities. The results from the presented studies suggest that there are strong and rather consistent indications that the developing nervous system is particularly vulnerable to insult from low levels of exposure to widespread environmental contaminants such as: phthalates, bisphenol A, brominated flame retardants, polycyclic aromatic hydrocarbons, gas cooking. Considering the suggested health effects, more epidemiologic data is urgently needed and, in the meantime, precautionary policies must be implemented.