Rice and millet cultivated in Ha Long Bay of Northern Vietnam 4000 years ago.

Research has generally outlined that the Neolithic East Asian farmers expanded into Southeast Asia, leading to substantial social and cultural transformations. However, the associated archaeobotanical evidence until now has been insufficient to clarify the exact timing, dispersal route, and farming package of the emergence of agriculture in Mainland Southeast Asia. To clarify these issues, the micro-plant remains of phytolith and starch from three Neolithic sites in Ha Long Bay were extracted and analyzed. This study validates the earliest evidence of co-cropping in northern Vietnam, involving the cultivation of rice together with foxtail millet at 4000 years BP or slightly earlier. Moreover, the results indicate that at least two patterns of subsistence strategy were practiced simultaneously during the initial farming phase in the region. The Trang Kenh people, a regional variant of the Phung Nguyen cultural group often have been seen as the first farmers in northern Vietnam, and they mainly practiced a cereal-based subsistence strategy with more vital cultural characteristics of southern China origin. Meanwhile, the Ha Long people, mainly composed of indigenous hunter-gatherer descendants, continued to utilize a wide range of their preferred plant resources such as taros, yams, and acorns, while they absorbed and incorporated new elements such as millet and rice into their food system. This study provides solid information to understand the diverse economic systems among different cultural groups in Vietnam.

Characterizing workplace exposures in Vietnamese women working in California nail salons.

OBJECTIVES: We engaged Vietnamese nail salon workers in a community-based participatory research (CBPR) study to measure personal and area concentrations of solvents in their workplace. METHODS: We measured average work-shift concentrations of toluene, ethyl acetate, and isopropyl acetate among 80 workers from 20 salons using personal air monitors. We also collected area samples from 3 salons using summa canisters. RESULTS: For personal measurements, the arithmetic mean was 0.53 parts per million (range = 0.02-5.50) for ethyl acetate, 0.04 parts per million (range = 0.02-0.15) for isopropyl acetate, and 0.15 parts per million (range = 0.02-1.0) for toluene. Area measurements were lower in comparison, but we detected notable levels of methyl methacrylate, a compound long banned from nail products. Predictors of solvent levels included different forms of ventilation and whether the salon was located in an enclosed building. CONCLUSIONS: Using a CBPR approach that engaged community members in the research process contributed to the successful recruitment of salon workers. Measured levels of toluene, methyl methacrylate, and total volatile organic compounds were higher than recommended guidelines to prevent health symptoms such as headaches, irritations, and breathing problems, which were frequently reported in this workforce.

Cancer incidence in female cosmetologists and manicurists in California, 1988-2005.

Health concerns have been pronounced for cosmetologists and manicurists, who are exposed daily to cosmetic products containing known or suspected human carcinogens and endocrine disruptors. In this retrospective cohort study, the authors used probabilistic record linkage between California's statewide cosmetology licensee and cancer surveillance files to identify newly diagnosed invasive cancers among female workforce members during 1988-2005. Rate ratios and 95% confidence intervals for cancer among workforce members compared with the general female population in California were estimated via Poisson regression. For comparison, site-specific proportional incidence ratios were computed. The authors identified 9,044 cancer cases in a cohort of 325,228 licensees. Rate ratios for all sites combined suggested lower incidence among both cosmetologists (rate ratio = 0.84, 95% confidence interval (CI): 0.82, 0.86) and manicurists (rate ratio = 0.87, 95% CI: 0.84, 0.90). Proportional incidence ratios were modestly elevated for thyroid cancer among all licensees (proportional incidence ratio = 1.13, 95% CI: 1.04, 1.23) and for lung cancer among manicurists (proportional incidence ratio = 1.21, 95% CI: 1.07, 1.36). Although there did not appear to be a cancer excess, these findings may be artifactually influenced by limitations in demographic information available from the licensee files. Additionally, the relatively young ages of cohort members and demographic shifts in the industry composition in recent years suggest a need for further follow-up.

Ancient jades map 3,000 years of prehistoric exchange in Southeast Asia.

We have used electron probe microanalysis to examine Southeast Asian nephrite (jade) artifacts, many archeologically excavated, dating from 3000 B.C. through the first millennium A.D. The research has revealed the existence of one of the most extensive sea-based trade networks of a single geological material in the prehistoric world. Green nephrite from a source in eastern Taiwan was used to make two very specific forms of ear pendant that were distributed, between 500 B.C. and 500 A.D., through the Philippines, East Malaysia, southern Vietnam, and peninsular Thailand, forming a 3,000-km-diameter halo around the southern and eastern coastlines of the South China Sea. Other Taiwan nephrite artifacts, especially beads and bracelets, were distributed earlier during Neolithic times throughout Taiwan and from Taiwan into the Philippines.

Craniometrics Reveal "Two Layers" of Prehistoric Human Dispersal in Eastern Eurasia.

This cranio-morphometric study emphasizes a "two-layer model" for eastern Eurasian anatomically modern human (AMH) populations, based on large datasets of 89 population samples including findings directly from ancient archaeological contexts. Results suggest that an initial "first layer" of AMH had related closely to ancestral Andaman, Australian, Papuan, and Jomon groups who likely entered this region via the Southeast Asian landmass, prior to 65-50 kya. A later "second layer" shared strong cranial affinities with Siberians, implying a Northeast Asian source, evidenced by 9 kya in central China and then followed by expansions of descendant groups into Southeast Asia after 4 kya. These two populations shared limited initial exchange, and the second layer grew at a faster rate and in greater numbers, linked with contexts of farming that may have supported increased population densities. Clear dichotomization between the two layers implies a temporally deep divergence of distinct migration routes for AMH through both southern and northern Eurasia.

Author Correction: Craniometrics Reveal "Two Layers" of Prehistoric Human Dispersal in Eastern Eurasia.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

A preliminary survey of Vietnamese nail salon workers in Alameda County, California.

In recent decades, the nail salon industry has been one of the fastest growing in the U.S. California has over 300,000 workers licensed to perform nail care services. Though little is known about their health, these workers routinely handle cosmetic products containing carcinogens and endocrine disruptors that may increase a woman's breast cancer risk. Additionally, an estimated 59-80% of California nail salons are run by Vietnamese women who face socio-cultural barriers that may compromise their workplace safety and health care access. In a pilot project designed to characterize Vietnamese nail salon workers in Alameda County, California in order to inform future health interventions and reduce occupational exposures, we conducted face-to-face surveys with a convenience sample of 201 Vietnamese nail salon workers at 74 salons. Of the workers surveyed, a majority reported that they are concerned about their health from exposure to workplace chemicals. Additionally, a sizeable proportion reported having experienced some health problem after they began working in the industry, particularly acute health problems that may be associated with solvent exposure (e.g. skin and eye irritation, breathing difficulties and headaches). Our findings highlight a critical need for further investigation into the breast cancer risk of nail salon workers, underscored by the workers' routine use of carcinogenic and endocrine-disrupting chemicals, their prevalent health concerns about such chemicals, and their high level of acute health problems. Moreover, the predominance of Vietnamese immigrant women in this workforce makes it an important target group for further research and health interventions.