Serum PCDD/F levels in metropolitan populations living near a municipal solid waste incinerator in Eastern China

Ambient exposure to polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) is suspected to cause adverse human health outcomes. Herein, serum samples from 40 residents in the neighborhood of a municipal solid waste incinerator (MSWI) in the metropolitan area were measured for PCDD/Fs. The mean toxic equivalent (TEQ) concentration of total PCDD/Fs in human serum samples was 16.8 pg TEQ/g lipid. Serum PCDD/F levels were significantly higher in residents adjacent to the MSWI than in those from areas far from the emission source (p < 0.01). In addition, there were no significant associations between serum PCDD/Fs levels and factors, such as gender, age, and BMI in donors. For non-occupationally exposed populations, OCDD and 1,2,3,7,8-PeCDD in serum are available as indicators of total PCDD/Fs and total TEQ, respectively. The atmospheric PCDD/Fs levels were within a relatively low range in areas upwind and downwind of the MSWI. The results of the principal component analysis showed a distinct difference in PCDD/F congener patterns between air and serum samples, suggesting inhalation exposure could have a limited influence on the human body burden. Our findings will deepen the current knowledge of endogenous PCDD/F exposure in urban populations, and also facilitate public health protection strategies near MSWIs.

Water, Sanitation, and Hygiene (WaSH) insecurity in unhoused communities of Los Angeles, California

BACKGROUND

Access to water and sanitation is a basic human right; however, in many parts of the world, communities experience water, sanitation, and hygiene (WaSH) insecurity. While WaSH insecurity is prevalent in many low and middle-income countries, it is also a problem in high-income countries, like the United States, as is evident in vulnerable populations, including people experiencing homelessness. Limited knowledge exists about the coping strategies unhoused people use to access WaSH services. This study, therefore, examines WaSH access among unhoused communities in Los Angeles, California, a city with the second-highest count of unhoused people across the nation.

METHODS

We conducted a cross-sectional study using a snowball sampling technique with 263 unhoused people living in Skid Row, Los Angeles. We calculated frequencies and used multivariable models to describe (1) how unhoused communities cope and gain access to WaSH services in different places, and (2) what individual-level factors contribute to unhoused people's ability to access WaSH services.

RESULTS

Our findings reveal that access to WaSH services for unhoused communities in Los Angeles is most difficult at night. Reduced access to overnight sanitation resulted in 19% of the sample population using buckets inside their tents and 28% openly defecating in public spaces. Bottled water and public taps are the primary drinking water source, but 6% of the sample reported obtaining water from fire hydrants, and 50% of the population stores water for night use. Unhoused people also had limited access to water and soap for hand hygiene throughout the day, with 17% of the sample relying on hand sanitizer to clean their hands. Shower and laundry access were among the most limited services available, and reduced people's ability to maintain body hygiene practices and limited employment opportunities. Our regression models suggest that WaSH access is not homogenous among the unhoused. Community differences exist; the odds of having difficulty accessing sanitation services is two times greater for those living outside of Skid Row (Adj OR: 2.52; 95% CI: 1.08-6.37) and three times greater for people who have been unhoused for more than six years compared to people who have been unhoused for less than a year (Adj OR: 3.26; 95% CI: 1.36-8.07).

CONCLUSION

Overall, this study suggests a need for more permanent, 24-h access to WaSH services for unhoused communities living in Skid Row, including toilets, drinking water, water and soap for hand hygiene, showers, and laundry services.

Epigenetic predictors of all-cause mortality are associated with objective measures of neighborhood disadvantage in an urban population

BACKGROUND

Neighborhood characteristics are robust predictors of overall health and mortality risk for residents. Though there has been some investigation of the role that molecular indicators may play in mediating neighborhood exposures, there has been little effort to incorporate newly developed epigenetic biomarkers into our understanding of neighborhood characteristics and health outcomes.

METHODS

Using 157 participants of the Detroit Neighborhood Health Study with detailed assessments of neighborhood characteristics and genome-wide DNA methylation profiling via the Illumina 450K methylation array, we assessed the relationship between objective neighborhood characteristics and a validated DNA methylation-based epigenetic mortality risk score (eMRS). Associations were adjusted for age, race, sex, ever smoking, ever alcohol usage, education, years spent in neighborhood, and employment. A secondary model additionally adjusted for personal neighborhood perception. We summarized 19 neighborhood quality indicators assessed for participants into 9 principal components which explained over 90% of the variance in the data and served as metrics of objective neighborhood quality exposures.

RESULTS

Of the nine principal components utilized for this study, one was strongly associated with the eMRS (β = 0.15; 95% confidence interval = 0.06-0.24; P = 0.002). This principal component (PC7) was most strongly driven by the presence of abandoned cars, poor streets, and non-art graffiti. Models including both PC7 and individual indicators of neighborhood perception indicated that only PC7 and not neighborhood perception impacted the eMRS. When stratified on neighborhood indicators of greenspace, we observed a potentially protective effect of large mature trees as this feature substantially attenuated the observed association.

CONCLUSION

Objective measures of neighborhood disadvantage are significantly associated with an epigenetic predictor of mortality risk, presenting a potential novel avenue by which neighborhood-level exposures may impact health. Associations were independent of an individual's perception of their neighborhood and attenuated by neighborhood greenspace features. More work should be done to determine molecular risk factors associated with neighborhoods, and potentially protective neighborhood features against adverse molecular effects.

Is the History of Substance Abuse Correlated with Neuropsychiatric Disorders and Co-morbid HIV Infection? An Urban Population Study

BACKGROUND

Human immunodeficiency virus (HIV) infection remains a serious immunological disease with new infections in the U.S. disproportionately reported in minority populations. For many years, the District of Columbia (DC) has reported the highest HIV infection rate in the nation. Drug abuse and addiction is also prevalent in DC and has traditionally been linked to HIV/AIDS because of the likelihood for opportunistic infections. Despite this data, the relationship between HIV status, drugs of abuse, and the incidence of neurological disorders are scarcely reported for minority populations.

METHOD

We carried out a retrospective study on the prevalence of substance abuse in HIV and their association with neuropsychiatric comorbidities in an African American subpopulation in Washington DC.

FINDINGS

Our data suggests an 86 percent prevalence of drug use in the HIV patients with neuropsychiatric comorbidities, with cocaine use being significantly higher in patients with major depressive disorder (MDD) and bipolar disorder (BD), whereas PCP use was associated with patients with schizophrenia. The mean CD4 count was elevated in patients with neuropsychiatric disease, and specifically in MDD patients. CD8 counts were elevated as expected for HIV status but were not influenced by disease diagnosis. A majority (2/3) of patients were on HAART therapy, however the records did not account for adherence.

CONCLUSION

These data suggest that neuropsychiatric comorbidities are independent of HIV disease progression but are correlated with certain illicit drugs of abuse.

Dual Contraceptive Method Use Among Youth in Alternative Schools

Dual contraceptive method use, or using a highly effective contraceptive method plus a barrier method like condoms, is gaining attention as a strategy for preventing unplanned pregnancy and sexually transmitted diseases. We investigated rates of dual method use among a sample of youth in urban alternative schools, and explored the relationship between dual method use and sexual partner type. The study analyzed data from 765 students enrolled in 11 district-run continuation high schools in northern California. We explored the association between dual method use and sexual partner type (steady only, a mix of steady and non-steady, and non-steady only) using logistic regression. Differences in dual rates by partner type were statistically significant, with higher rates of dual methods use reported among young people reporting non-steady sexual partners only, as compared to those with steady partners only. The data illustrate that young people in alternative school settings could gain from further intervention on the benefits, skills, and challenges of using two methods of contraception as opposed to one with both steady and non-steady sexual partners.

Behavioral and psychosocial effects of two middle school sexual health education programs at tenth-grade follow-up

PURPOSE

An earlier randomized controlled trial found that two middle school sexual education programs-a risk avoidance (RA) program and a risk reduction (RR) program-delayed initiation of sexual intercourse (oral, vaginal, or anal sex) and reduced other sexual risk behaviors in ninth grade. We examined whether these effects extended into 10th grade.

METHODS

Fifteen middle schools were randomly assigned to RA, RR, or control conditions. Follow-up surveys were conducted with participating students in 10th grade (n = 1,187; 29.2% attrition).

RESULTS

Participants were 60% female, 50% Hispanic, and 39% black; seventh grade mean age was 12.6 years. In 10th grade, compared with the control condition, both programs significantly delayed anal sex initiation in the total sample (RA: adjusted odds ratio [AOR], .64, 95% confidence interval [CI], .42-.99; RR: AOR, .65, 95% CI, .50-.84) and among Hispanics (RA: AOR, .53, 95% CI, .31-.91; RR: AOR, .82, 95% CI, .74-.93). Risk avoidance students were less likely to report unprotected vaginal sex, either by using a condom or by abstaining from sex (AOR: .61, 95% CI, .45-.85); RR students were less likely to report recent unprotected anal sex (AOR: .34, 95% CI, .20-.56). Both programs sustained positive impact on some psychosocial outcomes.

CONCLUSIONS

Although both programs delayed anal sex initiation into 10th grade, effects on the delayed initiation of oral and vaginal sex were not sustained. Additional high school sexual education may help to further delay sexual initiation and reduce other sexual risk behaviors in later high school years.