Single-chemical thresholds cannot comprehensively evaluate the risk of chemical mixture exposure in indoor air. Moreover, a large number of researches have focused on short-term and high-concentration co-exposure scenarios related to different species, based on diverse endpoints, which hampers the application and improvement of existing risk evaluation models of chemical mixture exposures. More importantly, current risk evaluation models are not user-friendly for construction practitioners who do not have sufficient toxicological knowledge. Therefore, in this study, an inhalation experiment system and a hazard index (HI) were developed to investigate the risks associated with low-concentration and long-term inhalation exposure scenarios of formaldehyde and benzene, individually and combined, based on Drosophila melanogaster mortality. The results showed that the system exhibited good reproducibility in providing stable exposure concentrations during D. melanogaster life cycle. Furthermore, in a range of experimental concentrations, the interaction between formaldehyde and benzene was additive or synergistic, which was concentration- and ratio-dependent. This study is of great significance in harmonising and providing toxicity data under long-term and low-concentration exposure scenarios, which is beneficial for establishing a new user-friendly risk evaluation model for indoor chemical mixture exposures. It should be noted that the proposed HI value could indicate the hazard degrees of long-term inhalation exposures of formaldehyde and benzene, individually and combined, to D. melanogaster. However, the applicability of this index requires further experiments to evaluate the exposure risks of other volatile organic compounds (VOCs) to D. melanogaster.

The present study evaluated the interactive effects of global change and heavy metals on the growth and development of three soybean [Glycine max (L.) Merrill] cultivars and the consequences on yield and food safety. Soybean cultivars (Alim 3.14 from Argentina, and ES Mentor and Sigalia, from Germany) were grown until maturity in heavy metals polluted soils from the Rhine Valley, Germany, at two CO₂ concentrations (400 and 550 ppm) and heat stress (HS) episodes (9 days with 10 °C higher than maximum regular temperature) during the critical growth period in controlled environmental chambers. Different morpho-physiological parameters, heavy metal concentration in aerial organs, seed quality parameters, and toxicological index were recorded. The results showed that no morphological differences were observed related to CO₂. Moreover, Alim 3.14 showed the highest yield under control conditions, but it was more sensitive to climatic conditions than the German cultivars, especially to heat stress which strongly reduces the biomass of the fruits. Heavy metals concentration in soil exceeds the legislation limits for agricultural soils for Cd and Pb, with 1.6 and 487 mg kg⁻¹ respectively. In all cultivars, soybeans accumulated Cd in its aerial organs, and it could be translocated to fruits. Cd concentration in seeds ranged between 0.6 and 2.4 mg kg⁻¹, which exceed legislation limits and with toxicological risk to potential Chinese consumers. Pb levels were lower than Cd in seeds (0.03–0.17 mg kg⁻¹), and the accumulation were concentrated in the vegetative organs, with 93% of the Pb incorporated. Moreover, pods accumulated 11 times more Pb than seeds, which suggests that they act as a barrier to the passage of Pb to their offspring. These results evidence that soybean can easily translocate Cd, but not Pb, to reproductive organs. No regular patterns were observed in relation to climatic influence on heavy metal uptake.

Trace metal (loid) contamination in the atmosphere is widely monitored, but there is a gap in understanding its long-term patterns, especially in North China, which is currently a global contamination hotspot mainly caused by heavy industry emissions and coal combustion. Herein, historical trends of atmospheric As, Cd, Cr, Cu, Hg, Ni, Pb and Zn contamination in North China over the past ∼500 years are comparatively studied with sediment cores from two subalpine lakes (Gonghai and Muhai). Arsenic, Pb, Cd and Hg were main pollutants according to Pb isotopes and enrichment factors. Mercury contamination has increased continuously since the late 1800s and increasing As, Pb and Cd contamination started in the 1950s in Gonghai. In contrast, the contamination in Muhai lagged two decades for As, Cd and Pb and a half-century for Hg behind that in Gonghai, although the trends were similar. This contamination lag was attributed to the low sensitivity of Muhai sediment to early weak atmospheric metal contamination under 2.1-fold higher detrital sedimentation. As, Pb and Cd contamination has intensified since the 1980s, and the metals showed similar sedimentary fluxes in the cores. However, sedimentary fluxes of Hg contamination were 3.4-fold higher in Gonghai than in Muhai due to combination with organic matter. No obvious Cr, Cu and Ni contamination in the cores was mainly because of the low atmospheric deposition from anthropogenic sources relative to detrital input, although some of their atmospheric emissions were higher than those of As, Cd and Hg. Atmospheric As, Pb and Cd contamination was mainly from domestic sources of coal combustion and nonferrous smelting. Mercury contamination was mainly from global and Asian sources in the first half of the 20th century, and domestic emissions gradually dominated Hg contamination after the mid-1900s.

Epidemiological studies have demonstrated a strong association of ambient fine particulate matter (PM₂.₅) exposure with the increasing mortality by ischemic heart disease (IHD), but the involved mechanisms remain poorly understood. Herein, we found that the chronic exposure of real ambient PM₂.₅ led to the upregulation of hypoxia-inducible factor-1 alpha (HIF-1α) protein in the myocardium of mice, accompanied by obvious myocardial injury and hypertrophy. Further data from the hypoxia-ischemia cellular model indicated that PM₂.₅-induced HIF-1α accumulation was responsible for the promotion of myocardial hypoxia injury. Moreover, the declined ATP level due to the HIF-1α-mediated energy metabolism remodeling from β-oxidation to glycolysis had a critical role in the PM₂.₅-increased myocardial hypoxia injury. The in-depth analysis delineated that PM₂.₅ exposure decreased the binding of prolyl hydroxylase domain 2 (PHD2) and HIF-1α and subsequent ubiquitin protease levels, thereby leading to the accumulation of HIF-1α. Meanwhile, factor-inhibiting HIF1 (FIH1) expression was down-regulated by PM₂.₅, resulting in the enhanced translocation of HIF-1α to the nucleus. Overall, our study provides valuable insight into the regulatory role of oxygen sensor-mediated HIF-1α stabilization and translocation in PM-exacerbated myocardial hypoxia injury, we suggest this adds significantly to understanding the mechanisms of haze particles-caused burden of cardiovascular disease.

Global warming is emerging as one of the most critical threats to terrestrial and marine species worldwide. This study assessed the effects of simulated warming events in culture on two seagrass species, Posidonia oceanica and Cymodocea nodosa, which play a key role in coastal ecosystems of the Mediterranean Sea. Changes in fatty acids as key metabolic indicators were assessed in specimens from two geographical populations of each species adapted to different in situ temperature regimes. Total fatty acid (TFA) content and composition were compared in C. nodosa and P. oceanica from natural populations and following exposure to heat stress in culture. After heat exposure, individuals of C. nodosa and P. oceanica adapted to colder temperatures in situ accumulated significantly more TFA than controls. For both species, the proportion of polyunsaturated fatty acids (PUFA) decreased, and the percentage of saturated fatty acids (SFA) increased significantly after the heat treatment. These results highlight that populations of both species living at warmest temperatures in situ were more thermo-tolerant and exhibited a greater capacity to cope with heat stress by readjusting their lipid composition faster. Finally, exposure of seagrasses to warmer conditions may induce a decrease in PUFA/SFA ratio which could negatively affect their nutritional value and generate important consequences in the healthy state of next trophic levels.