Time to kick the butt of the most common litter item in the world: Ban cigarette filters.

Cigarette filters offer no public health benefits, are single-use plastics (cellulose acetate) and are routinely littered. Filters account for a significant proportion of plastic litter worldwide, requiring considerable public funds to remove, and are a source of microplastics. Used cigarette filters can leech toxic chemicals and pose an ecological risk to both terrestrial and aquatic ecosystems. Bottom-up measures, such as focusing on consumer behaviour, are ineffective and we need to impose top-down solutions (i.e., bans) if we are to reduce the prevalence of this number one litter item. Banning filters offers numerous ecological, socioeconomic, and public health benefits.

Playing Favorites: Preferential Adsorption of Nonionic over Anionic Surfactants at the Liquid/Liquid Interface.

While many studies have investigated synergic interactions between surfactants in mixed systems, understanding possible competitive behaviors between interfacial components of binary surfactant systems is necessary for the optimized efficacy of applications dependent on surface properties. Such is the focus of these studies in which the surface behavior of a binary surfactant mixture containing nonionic (Span-80) and anionic (AOT) components adsorbing to the oil/water interface was investigated with vibrational sum-frequency (VSF) spectroscopy and surface tensiometry experimental methods. Time-dependent spectroscopic studies reveal that while both nonionic and anionic surfactants initially adsorb to the interface, anionic surfactants desorb over time as the nonionic surfactant continues to adsorb. Concentration studies that vary the ratio of Span-80 to AOT in bulk solution show that the nonionic surfactant preferentially adsorbs to the oil/water interface over the anionic surfactant. These studies have important implications for applications in which mixed surfactant systems are used to alter interfacial properties, such as pharmaceuticals, industrial films, and environmental remediation.

Twist and Stretch: Assignment and Surface Charge Sensitivity of a Water Combination Band and Its Implications for Vibrational Sum Frequency Spectra Interpretations.

The vibrational spectrum of water at hydrophobic/hydrophilic interfaces is crucial to understanding complex surface chemistry phenomena. Vibrational sum frequency (VSF) spectroscopy is a valuable nonlinear spectroscopic technique for exploring the details of vibrational spectra of molecules at surfaces. However, spectral assignments and analysis of VSF spectra are often more nuanced than in linear spectroscopy. This study is aimed at understanding the source of the broad VSF signal in the oil-water surface water spectrum at energies slightly higher than traditionally examined, beyond the unbound free OH oscillator of surface water molecules. Analyzing isotopic dilutions of the aqueous solvent with VSF spectroscopy, we demonstrate that this signal is due to a combination band of water stretch and libration motions. The spectral characteristics of this band are found to be highly sensitive to the sign and magnitude of the surface charge induced by adsorption of both anionic and cationic surfactants. The results have implications for VSF measurements of the C-H stretching vibrations of various adsorbates when studied with D2O as the aqueous solvent. Because the vibrational signal from the water combination band is dependent on surface charge, it is imperative to include the presence of the combination band when fitting surface spectra.

How Low Can You Go? Molecular Details of Low-Charge Nanoemulsion Surfaces.

Negative charge accumulation at aqueous-hydrophobic interfaces and its pH-dependent behavior are routinely ascribed to special adsorption properties of hydroxide ions. Mounting experimental and computational evidence, however, indicates that this negative charge accumulation is the result of surface-active impurities. If true, these impurities would obfuscate our fundamental understanding of the molecular structure and bonding environment at aqueous-hydrophobic interfaces. In this work, we describe the preparation and characterization of bare low-charge nanoemulsions (LCNEs), nanosized droplets of oil-absent emulsifiers. Electrophoretic mobility measurements of LCNE droplets in varying pH environments suggest that trace surface-adsorbed impurities are contributing to the lingering negative surface charge that leads to their marginal stability. We then use vibrational sum-frequency scattering spectroscopy to support this claim and to study the molecular structure and bonding environment of the interfacial aqueous and hydrophobic phases on both the LCNE surface and the surface of nanoemulsions with increasing amounts of adsorbed surfactants. For LCNE samples, our results show that interfacial water bonds more strongly to the oil phase on the droplet surface compared to similar planar interfaces. Interfacial oil molecules are found to orient mostly parallel to the bare droplet surface and reorganize upon surfactant adsorption. In summation, the results reported here provide a new look at the molecular structure and bonding of bare nanoemulsion surfaces and contribute to our evolving understanding of bare aqueous-hydrophobic interfaces.

Coming to Order: Adsorption and Structure of Nonionic Polymer at the Oil/Water Interface as Influenced by Cationic and Anionic Surfactants.

Polymer-surfactant mixtures are versatile chemical systems because of their ability to form a variety of complexes both in bulk solution and at surfaces. The adsorption and structure of polymer-surfactant complexes at the oil/water interface define their use surface chemistry applications. Previous studies have investigated the interactions between charged polyelectrolytes and surfactants; however, a similar level of insight into the interfacial behavior of nonionic polymers in mixed systems is lacking. The study herein uses vibrational sum frequency (VSF) spectroscopy to elucidate the molecular details of nonionic polyacrylamide (PAM) adsorption to the oil/water interface in the presence of surfactant. The polymer's adsorption and conformational structure at the interface is investigated as it interacts with cationic and anionic surfactants. Where the polymer will not adsorb to the interface on its own in solution, the presence of either cationic or anionic surfactant causes favorable adsorption of the polymer to the oil/water interface. VSF spectra indicate that the cationic surfactant interacts with PAM at the interface through charge-dipole interactions to induce conformational ordering of the polymer backbone. However, conformational ordering of polymer is not induced at the interface when anionic surfactant is present.

Formation and surface-stabilizing contributions to bare nanoemulsions created with negligible surface charge.

The stabilization of nanoemulsions, nanosized oil droplets dispersed in water, is commonly achieved through the addition of surfactants and polymers. However, nanoemulsions in the absence of emulsifiers have been observed to acquire a significant negative charge at their surface, which ultimately contributes to their stability. While the source of this negative charge is disputed to this day, its presence is taken as an inherent property of the aqueous-hydrophobic interface. This report provides a look at the molecular structure and bonding characteristics of bare aqueous-hydrophobic nanoemulsion interfaces. We report the creation of bare nanoemulsions with near zero surface charge, which are marginally stable for several days. The process of creating these low-charge nanoemulsions (LCNEs) required rigorous cleaning procedures and proper solvent storage conditions. Using vibrational sum-frequency scattering spectroscopy, we measure the structure and bonding of the interfacial aqueous and hydrophobic phases. The surfaces of these LCNE samples possess a measurable free OH vibration, not found in previous studies and indicative of a clean interface. Tuning the nanoemulsion charge through addition of anionic surfactants, modeling potential surface-active contaminants, we observe the free OH to disappear and a reorientation of the interfacial hydrophobic molecules at micromolar surfactant concentrations. Notably, the free OH vibration provides evidence for stronger dispersion interactions between water molecules and the hydrophobic phase at the LCNE surface compared with similar planar water-alkane interfaces. We propose the stronger bonding interactions, in addition to an ordered interfacial aqueous layer, contribute to the delayed droplet coalescence and subsequent phase separation.

Come Together: Molecular Details into the Synergistic Effects of Polymer-Surfactant Adsorption at the Oil/Water Interface.

The synergistic adsorption of polymers with surfactants at the oil/water interface has applications that range from oil remediation to targeted drug delivery. However, the inherent inaccessibility of the buried oil/water interface has challenged the development of a molecular-level understanding of the structure-function relationship of these systems. This study uses vibrational sum frequency spectroscopy to examine the molecular structure, orientation, and electrostatic effects of synergistic adsorption of the surfactant cetrimonium bromide (CTAB) and polymer poly(acrylic acid) (PAA) at a planar oil/water interface. Results demonstrate that coadsorption leads to a high degree of interfacial ordering of both the polymer and the surfactant and a subsequent alteration of the interfacial water bonding and orientation. Complementary zeta potential measurements provide further information about how surface partitioning of a charged polymer and a surfactant relates to their aggregation behavior in a bulk solution. With the CTAB concentration fixed but the PAA concentration variable, hydrophobic interactions result in a modest synergic coadsorption when CTAB is in excess. However, when the PAA carboxylate monomer concentration approaches that of CTAB, the electrostatic interactions between the components change the structure and increase the amount of adsorbed PAA until the interfacial charge is neutralized. This work reveals that the synergic adsorption behavior of this model polyacid/surfactant system arises from a combination of concentration-dependent hydrophobic and electrostatic forces working in tandem.

Is Institutional Delivery Protective Against Neonatal Mortality Among Poor or Tribal Women? A Cohort Study From Gujarat, India.

Objectives In low-income settings, neonatal mortality rates (NMR) are higher among socioeconomically disadvantaged groups. Institutional deliveries have been shown to be protective against neonatal mortality. In Gujarat, India, the access of disadvantaged women to institutional deliveries has increased. However, the impact of increased institutional delivery on NMR has not been studied here. This paper examined if institutional childbirth is associated with lower NMR among disadvantaged women in Gujarat, India. Methods A community-based prospective cohort of pregnant women was followed in three districts in Gujarat, India (July 2013-November 2014). Two thousand nine hundred and nineteen live births to disadvantaged women (tribal or below poverty line) were included in the study. Data was analyzed using multivariable logistic regression. Results The overall NMR was 25 deaths per 1000 live births. Multivariable analysis showed that institutional childbirth was protective against neonatal mortality only among disadvantaged women with obstetric complications during delivery. Among mothers with obstetric complications during delivery, those who gave birth in a private or public facility had significantly lower odds of having a neonatal death than women delivering at home (AOR 0.07 95% CI 0.01-0.45 and AOR 0.03, 95% CI 0.00-0.33 respectively). Conclusions for Practice Our findings highlight the crucial role of institutional delivery to prevent neonatal deaths among those born to disadvantaged women with complications during delivery in this setting. Efforts to improve disadvantaged women's access to good quality obstetric care must continue in order to further reduce the NMR in Gujarat, India.

Institutional review board challenges related to community-based participatory research on human exposure to environmental toxins: a case study.

BACKGROUND: We report on the challenges of obtaining Institutional Review Board (IRB) coverage for a community-based participatory research (CBPR) environmental justice project, which involved reporting biomonitoring and household exposure results to participants, and included lay participation in research. METHODS: We draw on our experiences guiding a multi-partner CBPR project through university and state Institutional Review Board reviews, and other CBPR colleagues' written accounts and conference presentations and discussions. We also interviewed academics involved in CBPR to learn of their challenges with Institutional Review Boards. RESULTS: We found that Institutional Review Boards are generally unfamiliar with CBPR, reluctant to oversee community partners, and resistant to ongoing researcher-participant interaction. Institutional Review Boards sometimes unintentionally violate the very principles of beneficence and justice which they are supposed to uphold. For example, some Institutional Review Boards refuse to allow report-back of individual data to participants, which contradicts the CBPR principles that guide a growing number of projects. This causes significant delays and may divert research and dissemination efforts. Our extensive education of our university Institutional Review Board convinced them to provide human subjects protection coverage for two community-based organizations in our partnership. CONCLUSIONS: IRBs and funders should develop clear, routine review guidelines that respect the unique qualities of CBPR, while researchers and community partners can educate IRB staff and board members about the objectives, ethical frameworks, and research methods of CBPR. These strategies can better protect research participants from the harm of unnecessary delays and exclusion from the research process, while facilitating the ethical communication of study results to participants and communities.

A new spin on research translation: the Boston Consensus Conference on Human Biomonitoring.

BACKGROUND: Translating research to make it more understandable and effective (research translation) has been declared a priority in environmental health but does not always include communication to the public or residents of communities affected by environmental hazards. Their unique perspectives are also commonly missing from discussions about science and technology policy. The consensus conference process, developed in Denmark, offers a way to address this gap. OBJECTIVES: The Boston Consensus Conference on Human Biomonitoring, held in Boston, Massachusetts, in the fall of 2006, was designed to educate and elicit input from 15 Boston-area residents on the scientifically complex topic of human biomonitoring for environmental chemicals. This lay panel considered the many ethical, legal, and scientific issues surrounding biomonitoring and prepared a report expressing their views. DISCUSSION: The lay panel's findings provide a distinct and important voice on the expanding use of biomonitoring. In some cases, such as a call for opt-in reporting of biomonitoring results to study participants, they mirror recommendations raised elsewhere. Other conclusions have not been heard previously, including the recommendation that an individual's results should be statutorily exempted from the medical record unless permission is granted, and the opportunity to use biomonitoring data to stimulate green chemistry. CONCLUSION: The consensus conference model addresses both aspects of a broader conception of research translation: engaging the public in scientific questions, and bringing their unique perspectives to bear on public health research, practice, and policy. In this specific application, a lay panel's recommendations on biomonitoring surveillance, communication, and ethics have practical implications for the conduct of biomonitoring studies and surveillance programs.

Toxic ignorance and right-to-know in biomonitoring results communication: a survey of scientists and study participants.

BACKGROUND: Exposure assessment has shifted from pollutant monitoring in air, soil, and water toward personal exposure measurements and biomonitoring. This trend along with the paucity of health effect data for many of the pollutants studied raise ethical and scientific challenges for reporting results to study participants. METHODS: We interviewed 26 individuals involved in biomonitoring studies, including academic scientists, scientists from environmental advocacy organizations, IRB officials, and study participants; observed meetings where stakeholders discussed these issues; and reviewed the relevant literature to assess emerging ethical, scientific, and policy debates about personal exposure assessment and biomonitoring, including public demand for information on the human health effects of chemical body burdens. RESULTS: We identify three frameworks for report-back in personal exposure studies: clinical ethics; community-based participatory research; and citizen science 'data judo.' The first approach emphasizes reporting results only when the health significance of exposures is known, while the latter two represent new communication strategies where study participants play a role in interpreting, disseminating, and leveraging results to promote community health. We identify five critical areas to consider in planning future biomonitoring studies. CONCLUSION: Public deliberation about communication in personal exposure assessment research suggests that new forms of community-based research ethics and participatory scientific practice are emerging.

Pollution comes home and gets personal: women's experience of household chemical exposure.

We report on interviews conducted with participants in a novel study about environmental chemicals in body fluids and household air and dust. Interviews reveal how personal and collective environmental history influence the interpretation of exposure data, and how participants fashion an emergent understanding of environmental health problems from the articulation of science and experience. To the illness experience literature, we contribute a framework for analyzing a new category of embodied narratives--"exposure experience"--that examines the mediating role of science. We update social scientific knowledge about social responses to toxic chemicals during a period in which science alters public understanding of chemical pollution. This article is among the first published accounts of participants' responses to learning personal exposure data, research identified as critical to environmental science and public health. Our findings raise the importance of reporting even uncertain science and underscore the value of a community-based reporting strategy

Improving disclosure and consent: "is it safe?": new ethics for reporting personal exposures to environmental chemicals.

The recent flood of research concerning pollutants in personal environmental and biological samples-blood, urine, breastmilk, household dust and air, umbilical cord blood, and other media-raises questions about whether and how to report results to individual study participants. Clinical medicine provides an expert-driven framework, whereas community-based participatory research emphasizes participants' right to know and the potential to inform action even when health effects are uncertain. Activist efforts offer other models. We consider ethical issues involved in the decision to report individual results in exposure studies and what information should be included. Our discussion is informed by our experience with 120 women in a study of 89 pollutants in homes and by interviews with other researchers and institutional review board staff.

Embodied health movements: new approaches to social movements in health.

Social movements organised around health-related issues have been studied for almost as long as they have existed, yet social movement theory has not yet been applied to these movements. Health social movements (HSMs) are centrally organised around health, and address: (a) access to or provision of health care services; (b) health inequality and inequity based on race, ethnicity, gender, class and/or sexuality; and/or (c) disease, illness experience, disability and contested illness. HSMs can be subdivided into three categories: health access movements seek equitable access to health care and improved provision of health care services; constituency-based health movements address health inequality and health inequity based on race, ethnicity, gender, class and/or sexuality differences; and embodied health movements (EHMs) address disease, disability or illness experience by challenging science on etiology, diagnosis, treatment and prevention. These groups address disproportionate outcomes and oversight by the scientific community and/or weak science. This article focuses on embodied health movements, primarily in the US. These are unique in three ways: 1) they introduce the biological body to social movements, especially with regard to the embodied experience of people with the disease; 2) they typically include challenges to existing medical/scientific knowledge and practice; and 3) they often involve activists collaborating with scientists and health professionals in pursuing treatment, prevention, research and expanded funding. This article employs various elements of social movement theory to offer an approach to understanding embodied health movements, and provides a capsule example of one such movement, the environmental breast cancer movement.