Rural-to-Urban Migration and Sexual Debut in Thailand

Migration from one’s parents’ home and sexual debut are common features of the transition to adulthood. Although many studies have described both of these features independently, few have examined the relationship between migration and sexual debut in a systematic manner. In this study, we explore this link for young adults in Thailand. With relatively high rates of internal migration, rapid modernization, a moderate HIV epidemic, and a declining average age of sexual debut, Thailand presents an instructive environment in which to examine migration and sexual debut. We use two waves of a longitudinal data set (2005 and 2007) that includes a subsample of young adults who migrated to urban areas during that period. We identify characteristics and behaviors associated with sexual debut and examine the role of migration on debut. Our approach reduces several common sources of bias that hamper existing work on both migration and sexual debut: (1) the longitudinal nature of the data enables us to examine the effects of characteristics that predate both behaviors of interest; (2) the survey on sexual behavior employed a technique that reduces response bias; and (3) we examine differences in debut by marital status. We find that migrants have a higher likelihood of sexual debut than nonmigrants.     

Health Selection,Migration, and HIV Infection in Malawi

Despite its importance in studies of migrant health, selectivity of migrants—also known as migration health selection—has seldom been examined in sub-Saharan Africa (SSA). This neglect is problematic because several features of the context in which migration occurs in SSA—very high levels of HIV, in particular—differ from contextual features in regions that have been studied more thoroughly. To address this important gap, we use longitudinal panel data from Malawi to examine whether migrants differ from nonmigrants in pre-migration health, assessed via SF-12 measures of mental and physical health. In addition to overall health selection, we focus on three more-specific factors that may affect the relationship between migration and health: (1) whether migration health selection differs by destination (rural-rural, rural-town, and rural-urban), (2) whether HIV infection moderates the relationship between migration and health, and (3) whether circular migrants differ in pre-migration health status. We find evidence of the healthy migrant phenomenon in Malawi, where physically healthier individuals are more likely to move. This relationship varies by migration destination, with healthier rural migrants moving to urban and other rural areas. We also find interactions between HIV-infected status and health: HIV-infected women moving to cities are physically healthier than their nonmigrant counterparts.     

Mental Health Consequences of International Migration for Vietnamese Americans and the Mediating Effects of Physical Health and Social Networks: Results From a Natural Experiment Approach

Although the existing literature on immigrant mental health is extensive, major substantive and methodological gaps remain. Substantively, there is little population-based research that focuses on the mental health consequences of migration for Vietnamese Americans. More generally, although a wide range of mental health problems among immigrants has been identified, the potential causal or mediating mechanisms underlying these problems remain elusive. This latter substantive shortcoming is related to a key methodological challenge involving the potentially confounding effects of selection on migration-related outcomes. This article addresses these challenges by employing a “natural experiment” design, involving comparisons among three population-based samples of Vietnamese immigrants, never-leavers, and returnees (N  =  709). Data were collected in Ho Chi Minh City and in New Orleans between 2003 and 2005. The study investigates the long-term impact of international migration on Vietnamese mental health, and the potential mediating effects of social networks and physical health on these migration-related outcomes. The results reveal both mental health advantages and disadvantages among Vietnamese immigrants relative to the two groups of Vietnamese nationals. Selection can be ruled out for some of these differences, and both social networks and physical health are found to play important explanatory roles.     

Race, socioeconomic status, and return migration to New Orleans after Hurricane Katrina

Hurricane Katrina struck New Orleans on the 29th of August 2005 and displaced virtually the entire population of the city. Soon after, observers predicted the city would become whiter and wealthier as a result of selective return migration, although challenges related to sampling and data collection in a post-disaster environment have hampered evaluation of these hypotheses. In this article, we investigate return to the city by displaced residents over a period of approximately 14 months following the storm, describing overall return rates and examining differences in return rates by race and socioeconomic status. We use unique data from a representative sample of pre-Katrina New Orleans residents collected in the Displaced New Orleans Residents Pilot Survey. We find that black residents returned to the city at a much slower pace than white residents even after controlling for socioeconomic status and demographic characteristics. However, the racial disparity disappears after controlling for housing damage. We conclude that blacks tended to live in areas that experienced greater flooding and hence suffered more severe housing damage which, in turn, led to their delayed return to the city. The full-scale survey of displaced residents being fielded in 2009–2010 will show whether the repopulation of the city was selective over a longer period.     

Community reaction to persons with HIV/AIDS and their parents: an analysis of recent evidence from Thailand

We systematically examine community reaction to persons living with HIV/AIDS (PHAs) and their older parents in Thailand. We focus on parents as well as PHAs because parents are major providers of care for their ill adult children. Our analyses are based on several sources of recently collected survey and qualitative data from a wide range of perspectives. We find important variations in community reaction to PHAs and their families, but overall these reactions are much more positive than is widely assumed. We conclude that much existing research on community reaction to AIDS neglects both a rich body of social theory on stigma and a strong tradition of population-based empirical research in sociology. Much existing research also fails to adequately distinguish between key aspects of the social settings where most AIDS cases occur and the social settings where most of the stereotypes surrounding AIDS-related stigma have originated. A closer marriage between empirical and theoretical approaches to social stigma is required to advance our understanding of this critically important dimension of the AIDS epidemic.     

Sexual activity among never-married men in northern Thailand

We use data collected in 1991 to investigate sexual activity among never-married men in Thailand, with a focus on age at first intercourse, characteristics of sexual partners, and conditions under which men visit prostitutes. We sampled men from a broad spectrum of northern Thai society, including university undergraduates, soldiers, and semiskilled/unskilled workers. We found that except for the students, the majority of each subsample is sexually experienced; prostitutes are the most common type of sexual partner for all groups. Alcohol consumption is associated with several measures of sexual activity. Condom use with prostitutes varies among the subsamples. Among men who have both prostitute and nonprostitute partners, the majority of those who do not use condoms with prostitutes also do not use condoms with their nonprostitute partners. We consider the implications of these results for the AIDS epidemic in Thailand.     

Evaluation of the Uncertainty in an Oral Reference Dose for Methylmercury Due to Interindividual Variability in Pharmacokinetics

An analysis of the uncertainty in guidelines for the ingestion of methylmercury (MeHg) due to human pharmacokinetic variability was conducted using a physiologically based pharmacokinetic (PBPK) model that describes MeHg kinetics in the pregnant human and fetus. Two alternative derivations of an ingestion guideline for MeHg were considered: the U.S. Environmental Protection Agency reference dose (RfD) of 0.1 g/kg/day derived from studies of an Iraqi grain poisoning episode, and the Agency for Toxic Substances and Disease Registry chronic oral minimal risk level (MRL) of 0.5 g/kg/day based on studies of a fish-eating population in the Seychelles Islands. Calculation of an ingestion guideline for MeHg from either of these epidemiological studies requires calculation of a dose conversion factor (DCF) relating a hair mercury concentration to a chronic MeHg ingestion rate. To evaluate the uncertainty in this DCF across the population of U.S. women of child-bearing age, Monte Carlo analyses were performed in which distributions for each of the parameters in the PBPK model were randomly sampled 1000 times. The 1st and 5th percentiles of the resulting distribution of DCFs were a factor of 1.8 and 1.5 below the median, respectively. This estimate of variability is consistent with, but somewhat less than, previous analyses performed with empirical, one-compartment pharmacokinetic models. The use of a consistent factor in both guidelines of 1.5 for pharmacokinetic variability in the DCF, and keeping all other aspects of the derivations unchanged, would result in an RfD of 0.2 g/kg/day and an MRL of 0.3 g/kg/day.