Secondary organic aerosol (SOA) is a major component of airborne fine particulate matter (PM 2.5 ) that contributes to adverse human health effects upon inhalation. Atmospheric ozonolysis of α-pinene, an abundantly emitted monoterpene from terrestrial vegetation, leads to significant global SOA formation; however, its impact on pulmonary pathophysiology remains uncertain. In this study, we quantified an increasing concentration response of three well-established α-pinene SOA tracers (pinic, pinonic, and 3-methyl-1,2,3-butanetricarboxylic acids) and a full mixture of α-pinene SOA in A549 (alveolar epithelial carcinoma) and BEAS-2B (bronchial epithelial normal) lung cell lines. The three aforementioned tracers contributed ∼57% of the α-pinene SOA mass under our experimental conditions. Cellular proliferation, cell viability, and oxidative stress were assessed as toxicological end points. The three α-pinene SOA molecular tracers had insignificant responses in both cell types when compared with the α-pinene SOA (up to 200 μg mL –1 ). BEAS-2B cells exposed to 200 μg mL –1 of α-pinene SOA decreased cellular proliferation to ∼70% and 44% at 24- and 48-h post exposure, respectively; no changes in A549 cells were observed. The inhibitory concentration-50 (IC 50 ) in BEAS-2B cells was found to be 912 and 230 μg mL –1 at 24 and 48 h, respectively. An approximate 4-fold increase in cellular oxidative stress was observed in BEAS-2B cells when compared with untreated cells, suggesting that reactive oxygen species (ROS) buildup resulted in the downstream cytotoxicity following 24 h of exposure to α-pinene SOA. Organic hydroperoxides that were identified in the α-pinene SOA samples likely contributed to the ROS and cytotoxicity. This study identifies the potential components of α-pinene SOA that likely modulate the oxidative stress response within lung cells and highlights the need to carry out chronic exposure studies on α-pinene SOA to elucidate its long-term inhalation exposure effects.

BackgrundMarginalized groups, such as nomadic populations across the world, have perhaps the least access to modern reproductive health (RH) services. This scoping review aims to identify barriers to access to RH services faced by nomadic populations from the existing literature and to highlight possible opportunities to address them.MethodsKey databases, including PubMed, Popline, Google Scholar, and Google Advanced were searched for relevant articles published between 2002 and 2019. A total 344 articles were identified through database online searches, and 31 were included in the review.ResultsNomadic people face complex barriers to healthcare access that can be broadly categorized as external (geographic isolation, socio-cultural dynamics, logistical and political factors) and internal (lifestyle, norms and practices, perceptions) factors. To effectively address the needs of nomadic populations, RH services must be available, accessible and acceptable through tailored and culturally sensitive approaches. A combination of fixed and mobile services has proven effective among mobile populations. Low awareness of modern RH services and their benefits is a major barrier to utilization. Partnership with communities through leveraging existing structures, networks and decision-making patterns can ensure that the programmes are effectively implemented.ConclusionFurther research is needed to better understand and address the RH needs of nomadic populations. Though existing evidence is limited, opportunities do exist and should be explored. Raising awareness and sensitization training among health providers about the specific needs of nomads is important. Improved education and access to information about the benefits of modern RH care among nomadic communities is needed. Ensuring community participation through involvement of nomadic women and girls, community leaders, male partners, and trained traditional birth attendants are key facilitators in reaching nomads. However, participatory programmes also need to be recognized and supported by governments and existing health systems.

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