This paper presents an extensive database of 450 chemicals reported in the grey literature (technical reports and documents) in association with the aircraft cabin environment. 72% (325 chemicals) of these exhibited toxic properties. The most affected target organs were skin (302 chemicals), eyes (294 chemicals), respiratory system (234 chemicals), and central nervous system (94 chemicals). The database includes available occupational exposure limits for a wide range of these pollutants (118). Results from technical reports on pollutant levels in aircraft were compared against their threshold health-based screening values. When performing a human health risk assessment on a chemical-by-chemical basis, there were no exceedances of average concentrations against workplace exposure limits. However, there were exceedances in maximum reported concentrations for ozone and acrolein. When chemical exposure was assessed additively for chemicals affecting the same target organs, the average concentrations did not exceed workplace limits. However, there were exceedances for maximum concentrations for compounds that targeted the eyes, skin, cardiovascular system, blood, and respiratory system. When performing a conservative additive risk assessment of endocrine disruptors (and potential endocrine disruptors), exceedances were observed when compared with no observed adverse effect levels (NOAEL) and workplace exposure thresholds established for confirmed endocrine disruption. Our results indicate that no single chemical is responsible for the adverse health effects reported by aircrew and instead point towards a combination of chemicals and additional factors. This work stresses the need for more comprehensive assessments that are coupled with epidemiological studies and risk assessments that consider exposure to multiple pollutants and specificities of the environment inside aircraft.

Dichlorodiphenyltrichloroethanes (DDTs) are ubiquitous in dust and air, which may be responsible for human dermal exposure to DDT. However, existing DDT exposure studies mainly concentrate on dietary exposure, and studies on skin exposure pathway are lacking. To gain further insight into the human exposure pathway of DDT, skin wipe and food samples were collected in a rural area in southern China, where new input of DDTs was found in both indoor and outdoor environments. The total DDT concentrations in skin wipes and foodstuffs varied from < method quantification limit (MQL) to 1470 ng/m² and from < MQL to 12.8 ng/g wet weight, respectively. In foodstuffs, egg showed the highest DDT concentration, while forehead showed the highest DDT concentration in the four skin locations. p,p’-DDT was predominant in the hand and forearm wipes, while p,p’-DDE was dominant in the forehead, upper arm, and food samples. The total DDT daily absorption median levels via dermal contact, hand-mouth contact, and food consumption were 0.187, 0.0237, and 0.994 ng/kg/d, respectively. Organic eggs and wild fish contaminated by DDTs released locally are the main sources of human dietary exposure to DDTs, and reducing the intake of contaminated fish and eggs would help to significantly reduce human DDT absorption; in this case, the contribution of dermal exposure cannot be not negligible.

Air pollution is a major environmental and public health issue in urban areas. Biomonitoring using trees has been widely used to determine atmospheric pollution due to its advantages of low cost, high spatial distribution, and accumulation of a wide range of air contaminants. However, challenges exist in applying the data obtained from biomonitoring trees, including differences in pollutant concentrations in samples of the same species from different locations, and the influence of biological and environmental parameters on metal accumulation. This study aims to inform the design of biomonitoring sampling for urban air quality studies and increase their applications to exposure assessment. Specifically, the study evaluates the variation in metal concentration in tree organs of two regionally relevant tree species (Picea pungens and Populus Alba), explores the implications of different aspects of field sampling, such as variation within tree stands, tree age, and develops a reference specimen to establish threshold values for differentiating between background levels and increased exposure. The results provide insight into the complexity of using biomonitoring trees for exposure assessment and the importance of considering multiple factors in study design.

We report concentrations of organophosphate esters (OPEs) in air from living rooms, bedrooms, and offices in Birmingham, UK. To place concentrations in these commonly frequented indoor microenvironments in context, we also measured the same OPEs in air samples collected from an outdoor location on the University of Birmingham campus. Concentrations of tris(2-chloroethyl) phosphate (TCEP), tris(2-chloroisopropyl) phosphate (TCIPP), and tri-n-butyl phosphate (TnBP) in indoor air significantly exceeded (P > 0.05) those in outdoor air. In contrast, concentrations of tris(1,3-dichloroisopropyl) phosphate (TDCIPP), triphenyl phosphate (TPhP), and 2-ethylhexyl diphenyl phosphate (EHDPP) in indoor and outdoor air were statistically indistinguishable (P < 0.05). Comparison of estimates of human exposure via inhalation derived from our data with previous estimates of exposure via dust ingestion, diet, drinking water, and dermal contact with furniture reveals that inhalation is the most important contributor to aggregate UK adult exposure to TCIPP (85% _exposure) and TCEP (67% _exposure). While average aggregate exposures of UK adults were well below health-based reference dose values, continued evaluation of human exposure is recommended as high-end exposures of some individuals (e.g., those inhabiting microenvironments containing concentrations of TCIPP at the high end of the range reported here) likely exceed substantially average exposures.