The exposure-response relationship between temperature and childhood hand, foot and mouth disease: A multicity study from mainland China.

BACKGROUND: Hand, foot and mouth disease (HFMD) is a rising public health issue in the Asia-Pacific region. Numerous studies have tried to quantify the relationship between meteorological variables and HFMD but with inconsistent results, in particular for temperature. We aimed to characterize the relationship between temperature and HFMD in various locations and to investigate the potential heterogeneity. METHODS: We retrieved the daily series of childhood HFMD counts (aged 0-12 years) and meteorological variables for each of 143 cities in mainland China in the period 2009-2014. We fitted a common distributed lag nonlinear model allowing for over dispersion to each of the cities to obtain the city-specific estimates of temperature-HFMD relationship. Then we pooled the city-specific estimates through multivariate meta-regression with city-level characteristics as potential effect modifiers. RESULTS: We found that the overall pooled temperature-HFMD relationship was shown as an approximately inverted V shape curve, peaking at the 91th percentile of temperature with a risk ratio of 1.30 (95% CI: 1.23-1.37) compared to its 50th percentile. We found that 68.5% of the variations of city-specific estimates was attributable to heterogeneity. We identified rainfall and altitude as the two main effect modifiers. CONCLUSIONS: We found a nonlinear relationship between temperature and HFMD. The temperature-HFMD relationship varies depending on geographic and climatic conditions. The findings can help us deepen the understanding of weather-HFMD relationship and provide evidences for related public health decisions

Biomarker records of D5-6 columns in the eastern Antarctic Peninsula waters: responses of planktonic communities and bio-pump structures to sea ice global warming in the past centenary

Molecular biomarkers (e.g., isoprenoid glycerol dialkyl glycerol tetraethers (iGDGTs) and proxies, such as di-unsaturated to tri-unsaturated highly branched isoprenoids (D/T) ratio, total organic carbon, δ13C and ice-rafted debris (IRD)) were used to reconstruct the dominant phytoplankton (diatoms, dinoflagellates and coccolithophores), phytoplankton and zooplankton productivity, biological pump structure, and archaea assemblage (Euryarchaeota and Crenarchaeota) from a marine sediment core (D5-6) dated with 210Pb (1922–2012). We characterized the environmental response to sea ice variations/global warming off the eastern Antarctic Peninsula. The results showed that (1) the biomarkers brassicasterol (average = 519.79 ng·g−1), dinosterol (average = 129.68 ng·g−1) and C37 alkenones (average = 40.53 ng·g−1) reconstructed phytoplankton (average = 690.00 ng·g−1) and zooplankton (cholesterol average = 669.25 ng·g−1) productivity. The relative contribution to productivity by different phytoplankton groups was diatoms > dinoflagellates > coccolithophores. This is consistent with field surveys showing that diatoms dominate the phytoplankton in waters adjacent to the Antarctic Peninsula. (2) The relative abundances of different highly branched isoprenoids reflected the contributions of sea ice algae and open water phytoplankton (D/T = 1.2–30.15). Phytoplankton productivity and sea ice showed a good linear relationship with a negative correlation, indicating that more open water during periods of warming and reduced sea ice cover led to an enhanced biological pump. (3) Over the past 100 years, phytoplankton productivity and zooplankton biomass increased. This trend was particularly evident in the last 50 years, corresponding to increased global warming, and showed a negative correlation with IRD and D/T. This suggests that with decreasing sea ice coverage in a warming climate, diatom biomass greatly increased. Coccolithophore/diatom values and the ratio of C37 alkenones to total phytoplankton productivity decreased, indicating the proportion of coccolithophores in the phytoplankton community decreased. The reduction in coccolithophores changes the phytoplankton assemblage and affects the overall efficiency of the biological pump and carbon storage. (4) The results also showed that the abundance of iGDGTs and archaea phyla (Euryarchaeota and Crenarchaeota) showed consistent changes over the past 100 years in response to global warming. Since 1972, trends in archaea, phytoplankton and zooplankton showed variations but a consistent decline. Whether their response to the changing climate off the Antarctic Peninsula involves interactions and influence among different marine biological groups remains an open question. As a result of global warming and reductions in Antarctic sea ice, the relative effectiveness of the Antarctic biological pump can significantly affect global ocean carbon storage