We studied the effect of estimated PM₁₀ on respiratory infections in children from Cordoba, Argentine as well as the influence of weather factors, socio-economic conditions and education. We analyzed upper and lower respiratory infections and applied a time-series analysis with a quasi-Poisson distribution link function. To control for seasonally varying factors we fitted cubic smoothing splines of date. We also examined community-specific parameters and differences in susceptibility by sex. We found a significant association between particles and respiratory infections. This relationship was affected by mean temperature, atmospheric pressure and wind speed. These effects were stronger in fall, winter and spring for upper respiratory infections while for lower respiratory infections the association was significant only during spring. Low socio-economic conditions and low education levels increased the risk of respiratory infections. These findings add useful information to understand the influence of airborne particles on children health in developing countries.

Polychlorinated naphthalenes (PCNs) are now under review by the Stockholm Convention as a candidate for POPs for their persistence, toxicity, bioaccumulation, and long-range atmospheric transport. Data regarding PCN levels and their environmental fate are sparse in China. The PCN concentration and distribution in soils of the Pearl River Delta were reported, and the average total concentration was 59.9 ± 86.7 pg/g. Tri-CNs was the dominant homologue group, and CN 24 was the most abundant congener. A gradient of PCN levels between more and less developed areas was observed. Based on fugacity fraction results, CN 51 is proposed as a possible source marker for specific combustion emissions. Air-soil exchange of PCNs was estimated by calculating the soil and air fugacity. Fugacity fraction values indicated that tri- to penta-CNs were closer to equilibrium in winter and toward net volatilization in summer, while hexa-CNs experienced net air-to-soil transfer in both seasons.

Long-term fluxes of CO₂, and combined short-term fluxes of CH₄ and CO₂ were measured with the eddy covariance technique in the city centre of Florence. CO₂ long-term weekly fluxes exhibit a high seasonality, ranging from 39 to 172% of the mean annual value in summer and winter respectively, while CH₄ fluxes are relevant and don’t exhibit temporal variability. Contribution of road traffic and domestic heating has been estimated through multi-regression models combined with inventorial traffic and CH₄ consumption data, revealing that heating accounts for more than 80% of observed CO₂ fluxes. Those two components are instead responsible for only 14% of observed CH₄ fluxes, while the major residual part is likely dominated by gas network leakages. CH₄ fluxes expressed as CO₂ equivalent represent about 8% of CO₂ emissions, ranging from 16% in summer to 4% in winter, and cannot therefore be neglected when assessing greenhouse impact of cities.

The concentration and composition of PAHs emitted from biomass cooking fuel were characterized in a rural non-smoking household in northern China. Twenty-two parent PAHs (pPAHs), 12 nitro-PAHs (nPAHs), and 4 oxy-PAHs (oPAHs) were measured in the kitchen, bedroom, and outdoors during both summer and winter. The most severe contamination occurred in the kitchen in the winter, where the daily mean concentrations of pPAHs, nPAHs, and oPAHs were 7500 ± 4100, 38 ± 29, and 8400 ± 9200 ng/m³, respectively. Our results suggest that the nPAHs were largely from secondary formation in ambient air while oPAHs were either from primary emission of biomass burning or secondary formation from pPAHs in the kitchen. The daily mean benzo(a)pyrene equivalent exposure concentration was as high as 200 ± 160 ng/m³ in the winter for the housewife who did the cooking compared to 59 ± 37 ng/m³ for the control group that did not cook.

The interaction of atmospheric sulphur (S) was investigated within the canopies of two boreal forests in Québec, Canada. The net canopy exchange approach, i.e. the difference between S–SO₄ in throughfall and precipitation, suggests high proportion of dry deposition in winter (up to 53%) as compared to summer (1–9%). However, a 3.5‰ decrease in δ¹⁸O–SO₄ throughfall in summer compared to incident precipitation points towards a much larger proportion of dry deposition during the warm season. We suggest that a significant fraction of dry deposition (about 1.2 kg ha⁻¹ yr⁻¹, representing 30–40% of annual wet S deposition) which contributed to the decreased δ¹⁸O–SO₄ in throughfall was taken up by the canopy. Overall, these results showed that, contrary to what is commonly considered, S interchanges in the canopy could be important in boreal forests with low absolute atmospheric S depositions.

Short chain chlorinated paraffins (SCCPs) are semi-volatile chemicals that are considered persistent in the environment, potential toxic and subject to long-range transport. This study investigates the concentrations and gas-particle partitioning of SCCPs at an urban site in Beijing during summer and wintertime. The total atmospheric SCCP levels ranged 1.9–33.0 ng/m³ during wintertime. Significantly higher levels were found during the summer (range 112–332 ng/m³). The average fraction of total SCCPs in the particle phase (ϕ) was 0.67 during wintertime but decreased significantly during the summer (ϕ = 0.06). The ten and eleven carbon chain homologues with five to eight chlorine atoms were the predominant SCCP formula groups in air. Significant linear correlations were found between the gas-particle partition coefficients and the predicted subcooled vapor pressures and octanol–air partition coefficients. The gas-particle partitioning of SCCPs was further investigated and compared with both the Junge–Pankow adsorption and Kₒₐ-based absorption models.

Levoglucosan was present in all samples and its concentrations showed a pronounced annual cycle with maximum levels in the cold season. The annual percentage of ratios of levoglucosan to OC ranged from 0.04 to 9.75% evidencing a major contribution of biomass burning to the aerosol OC during the winter. In the urban-background site, OC was strongly correlated with EC in winter, suggesting that the major fraction of OC was generated as primary particles along with EC. A background levoglucosan component showed that biomass burning was continuously taking place in all the investigated sites. The biomass burning contribution to the Tuscany aerosol was made up of a background component and an additional component during winter probably due to wood burning for domestic heating.

We investigated the sediment–seawater solute flux at five sites in the polluted Avon–Heathcote Estuary, New Zealand, to provide a point of comparison for future studies of the effects of the closure of a major wastewater outfall into the estuary. Sediments collected in winters 2007 and 2008, and summer 2008, ranked consistently in organic matter content. Microelectrode profiling and sediment-core incubations revealed (1) a dominant role of microphytes in regulating solute flux causing significant differences in the dark and light sediment O₂ consumption (Rd, Rₗ), total sediment O₂ utilisation (TOUd, TOUₗ), and inorganic nutrient flux, (2) consistent ranking of sites in solute flux, and (3) a clear solute-flux signature of the wastewater effluent. Sediment near the wastewater outfall exhibited the highest absolute R and TOU, the lowest ratio Rₗ/Rd, the highest dark efflux of dissolved reactive phosphorus and ammonium, and the highest dark and light uptake of nitrate+nitrite.

Recent changes in ocean temperature have impacted marine ecosystem function globally. Nevertheless, the responses have depended upon the rate of change of temperature and the season when the changes occur, which are spatially variable. A rigorous statistical analysis of sea surface temperature observations over 25years was used to examine spatial variability in overall and seasonal temperature trends within the wider Caribbean. The basin has experienced high spatial variability in rates of change of temperature. Most of the warming has been due to increases in summer rather than winter temperatures. However, warming was faster in winter in the Loop Current area and the south-eastern Caribbean, where the annual temperature ranges have contracted. Waters off Florida, Cuba and the Bahamas had a tendency towards cooling in winter, increasing the amplitude of annual temperature ranges. These detailed patterns can be used to elucidate ecological responses to climatic change in the region.

The microbiological pollution of coastal waters is a major problem, especially in shellfish areas. This article shows the faecal contamination in bivalves from the Ria Formosa Lagoon (south coast of Portugal) along 20years (1990–2009). The highest values of Escherichia coli in bivalves were obtained during the 90s, related with the discharge of untreated wastewaters and agricultural runoff. In the 2000s contamination levels decreased, with 83% of the population already served by new or remodelled sewage treatment plants. The highest levels were found in bivalves close to the largest city, where punctual and diffuse contamination sources still exist. Bivalves from the less impacted site showed the lowest contamination, an area with more water renewal. Seasonally, the highest levels were in autumn and winter, due to the runoff of waters from rainfall. These were opposite to those in spring and summer, when the highest temperatures and salinity showed a bactericidal effect.