Perfluorochemicals and human semen quality: the LIFE study.

Background: The relation between persistent environmental chemicals and semen quality is evolving, although limited data exist for men recruited from general populations.

Objectives: We examined the relation between perfluorinated chemicals (PFCs) and semen quality among 501 male partners of couples planning pregnancy.

Methods: Using population-based sampling strategies, we recruited 501 couples discontinuing contraception from two U.

Preconception maternal and paternal exposure to persistent organic pollutants and birth size: the LIFE study.

Background: Persistent organic pollutants (POPs) are developmental toxicants, but the impact of both maternal and paternal exposures on offspring birth size is largely unexplored.

Objective: We examined associations between maternal and paternal serum concentrations of 63 POPs, comprising five major classes of pollutants, with birth size measures.

Methods: Parental serum concentrations of 9 organochlorine pesticides, 1 polybrominated biphenyl (PBB), 7 perfluoroalkyl chemicals (PFCs), 10 polybrominated diphenyl ethers (PBDEs), and 36 polychlorinated biphenyls (PCBs) were measured before conception for 234 couples.

Evaluating geostatistical modeling of exceedance probability as the first step in disease cluster investigations: very low birth weights near toxic Texas sites.

Background: The first step in evaluating potential geographic clusters of disease calls for an evaluation of the disease risk comparing the risk in a defined location to the risk in neighboring locations. Environmental exposures, however, represent continuous exposure levels across space not an exposure with a distinct boundary. The objectives of the current study were to adapt, apply and evaluate a geostatistical approach for identifying disease clusters.

Urinary bisphenol A, phthalates, and couple fecundity: the Longitudinal Investigation of Fertility and the Environment (LIFE) Study.

Objective: To assess the relationship between environmental chemicals and couple fecundity or time to pregnancy (TTP).

Design: Prospective cohort.

Setting: Communities of targeted populations with reported exposure.

Higher urinary lignan concentrations in women but not men are positively associated with shorter time to pregnancy.

Phytoestrogens have been associated with subtle hormonal changes, although effects on fecundity are unknown. Our objective was to evaluate the association between male and female urinary phytoestrogen (isoflavone and lignan) concentrations and time to pregnancy (TTP) in a population-based cohort of 501 couples desiring pregnancy and discontinuing contraception. Couples were followed for 12 mo or until pregnancy.

Persistent environmental pollutants and couple fecundity: the LIFE study.

Background: Evidence suggesting that persistent environmental pollutants may be reproductive toxicants underscores the need for prospective studies of couples for whom exposures are measured.

Objectives: We examined the relationship between selected persistent pollutants and couple fecundity as measured by time to pregnancy.

Methods: A cohort of 501 couples who discontinued contraception to become pregnant was prospectively followed for 12 months of trying to conceive or until a human chorionic gonadotrophin (hCG) test confirmed pregnancy.

Heavy metals and couple fecundity, the LIFE Study.

The effect of heavy metals at environmentally relevant concentrations on couple fecundity has received limited study despite ubiquitous exposure. In 2005-2009, couples (n=501) desiring pregnancy and discontinuing contraception were recruited and asked to complete interviews and to provide blood specimens for the quantification of cadmium (μg L(-1)), lead (μg dL(-1)) and mercury (μg L(-1)) using inductively coupled plasma-mass spectrometry. Couples completed daily journals on lifestyle and intercourse along with menstruation and pregnancy testing for women.

Designing prospective cohort studies for assessing reproductive and developmental toxicity during sensitive windows of human reproduction and development--the LIFE Study.

The relationship between the environment and human fecundity and fertility remains virtually unstudied from a couple-based perspective in which longitudinal exposure data and biospecimens are captured across sensitive windows. In response, we completed the LIFE Study with methodology that intended to empirically evaluate a priori purported methodological challenges: implementation of population-based sampling frameworks suitable for recruiting couples planning pregnancy; obtaining environmental data across sensitive windows of reproduction and development; home-based biospecimen collection; and development of a data management system for hierarchical exposome data. We used two sampling frameworks (i.

Marijuana use and testicular germ cell tumors.

Background: Since the early 1970s, the incidence of testicular germ cell tumors (TGCTs) in the United States has been increasing; however, potential environmental exposures accounting for this increase have not been identified. A previous study reported a significant association between frequent and long-term current marijuana users and TGCT risk. The purpose of this study was to evaluate the relation between marijuana use and TGCTs in a hospital-based case-control study.

Contaminant profiles in Southeast Asian immigrants consuming fish from polluted waters in northeastern Wisconsin.

Recent immigrants to the USA from Southeast Asia may be at higher risk of exposure to fish-borne contaminants including polychlorinated biphenyls (PCBs), p, p'-dichlorodiphenyldichloroethene (DDE) and methylmercury (MeHg) because of their propensity to engage in subsistence fishing. Exposure to contaminants was assessed in men and women of Hmong descent living in Green Bay, Wisconsin, where the Fox River and lower Green Bay are contaminated with PCBs, and to a lesser extent with mercury. Serum samples from 142 people were analyzed for PCBs and p,p'-DDE by capillary column gas chromatography with electron capture detection (ECD).

Intra- and inter-individual variability of urinary phthalate metabolite concentrations in Hmong women of reproductive age.

The reproducibility of urinary phthalate metabolite concentrations has not been well characterized in non-pregnant women of reproductive age. Our primary study objectives were to describe the distribution of urinary phthalate metabolites concentrations among a population of Hmong women of reproductive age, and to evaluate intra- and inter-individual variability of phthalate metabolite concentrations. Ten phthalate metabolites were measured in first-morning urine samples collected from 45 women and 20 of their spouses, who were members of the Fox River Environment and Diet Study cohort in Green Bay, Wisconsin.

Prenatal and perinatal risk factors and testicular cancer: a hospital-based case-control study.

Some evidence exists to support the hypothesis that elevated levels of circulating maternal estrogens during early pregnancy may increase risk of testicular germ cell cancer. However, the results from studies evaluating maternal factors have been mixed. We evaluated maternal factors, particularly those associated with excess estrogen levels, as risk factors for testicular cancer.

Reproductive characteristics of Southeast Asian immigrants before and after migration.

We describe the reproductive health and practices of Hmong immigrants before and after migration to the United States. Data were gathered as part of an ongoing study on the impact of perinatal exposure to environmental chemicals on children's health in Hmong residents of Green Bay, Wisconsin between August 1999 and May 2002. Of the 742 pregnancies reported by 141 reproductive-aged couples, 669 were live births.

The influence of age at exposure to PBBs on birth outcomes.

The determination of critical windows of susceptibility to environmental chemical exposures and health has become a major public health focus. This study examined the association between early age at exposure to polybrominated biphenyls (PBBs) and subsequent birth weight and gestational length in offspring among females. The study population consisted of 1111 births that occurred among 560 women enrolled in the Michigan PBB Cohort from 1975 to 1994.

A cohort study of injuries in migrant farm worker families in South Texas.

Purpose: This cohort study estimated the frequency of and risk factors for work injuries among migrant farmworker families over a two-year period.

Methods: The cohort consisted of 267 families. Bilingual interviewers asked mothers to respond for their family soliciting demographic, psychosocial, employment, and work-related injury information.

Prospective pregnancy study designs for assessing reproductive and developmental toxicants.

The determinants of successful human reproduction and development may act as early as periconceptionally, underscoring the need to capture exposures during these critical windows when assessing potential toxicants. To identify such toxicants, couples must be studied longitudinally prior to conception without regard to a couple's ability to ascertain a clinically recognized pregnancy. We examined the utility and feasibility of prospective pregnancy study designs by conducting a systematic review of the literature to summarize relevant information regarding the planning, implementation, and success of previously published prospective pregnancy studies.

Off to a good start: the influence of pre- and periconceptional exposures, parental fertility, and nutrition on children's health.

The scientific community is developing a compelling body of evidence that shows the importance of the in utero environment (including chemical and hormonal levels) to the ultimate health of the child and even of the aging adult. This article summarizes the evidence that shows this impact begins with conception. Only a full life-cycle evaluation will help us understand these impacts, and only such an understanding will produce logically prioritized mitigation strategies to address the greatest threats first.

A longitudinal examination of factors related to changes in serum polychlorinated biphenyl levels.

Consumption of sport-caught fish from the Great Lakes is a recognized source of human exposure to polychlorinated biphenyls (PCBs). Understanding temporal changes in PCB body burden is crucial for evaluating exposure levels and augmenting validity of studies investigating their relationship to adverse health effects. Using data collected from 1980 to 1995, we evaluated longitudinal changes in serum PCB levels among 179 fisheaters and non-fisheaters of the Michigan Fisheater Cohort.