Heavy metal levels in milk and dairy products and health risk assessment: A systematic review of studies in China.

Previous studies have indicated that heavy metal levels in milk vary partly depending on environmental metal concentrations. Given the increasing consumption of milk in China, it is essential to pay attention to milk safety. We performed a systematic review of relevant published studies to evaluate the heavy metal levels in milk and dairy products and the associated health risks, discuss environmental sources of heavy metals, and propose future research directions. A literature search was implemented in the Web of Science Core Collection and PubMed using multiple keywords such as "metal," "milk," "dairy products," and "China". A total of 16 published studies that analyzed metal levels in milk and dairy products in 20 provincial administrative regions were included. Most studies detected toxic heavy metals in milk and dairy products samples, including mercury, lead, cadmium, chromium, and arsenic. The lead concentration in milk from these studies did not exceed the Chinese standard for milk. However, three studies detected relatively high lead levels in both commercial and raw milk, exceeding the European Commission standard. The polluted environment surrounding the farm, feed, and packaging materials are likely sources of metals in milk and dairy products. The hazard index for the 11 analyzed metal elements in milk and dairy products was lower than 1, indicating negligible non-carcinogenic health risks from exposure to these metals. Children are at a higher risk than adults. This review illustrates that research in this field is limited to China. More research should be conducted in the future, such as evaluating the contribution of each environmental source of metal in milk and dairy products.

Health risks and economic losses from cold spells in China.

BACKGROUND: Cold significantly increases the risk of mortality. However, the health risks associated with cold spells, persistent and extreme cold temperature events, have yet to be investigated in detail. METHODS: Meteorological and mortality data was collated from 280 counties in China from 2013 through 2019. GLM (Generalized Linear Models) was used to calculate county-level exposure-response relationships for nine different cold spell definitions. Next, we estimated the exposure-response associations between cold spells and mortality in national, Southern, and Northern China. Based on exposure-response relationships, along with the population and mortality data, we then calculated the number of excess deaths due to the cold spell of 2839 counties across China in 2018. Then, we calculated the loss of VSL (value of a statistical life) in each province. RESULTS: We identified that P5day7 was the cold spell definition that was associated with the highest health in China. Compared with non-cold spell days, the risk of non-accidental mortality, circulatory mortality, and respiratory mortality, on cold spell days increased by 17.4% (95% confidence interval [CI]: 15.8%, 19.0%), 20.8% (95%CI: 18.8%, 23.0%), and 22.7% (95%CI: 19.5%, 25.9%) respectively at lag 7 day in the South. In the North, the risk increased by 13.0% (95% CI: 11.0%, 15.0%), 13.8% (95% CI: 11.4%, 16.2%), and 21.0% (95% CI: 16.6%, 25.6%), respectively. The number of related deaths in China were 57,783, 29,827, and 10,922. The corresponding VSLs were 229,195, 118,322, and 43,315 million CNY (Chinese Yuan), thus accounting for 0.25%, 0.13%, and 0.05% of national GDP (Gross Domestic Product). CONCLUSION: Cold spells have caused a severe epidemiological and economic burden in China. South China should pay more attention to the health risks associated with cold spells.

The exceptional heatwaves of 2017 and all-cause mortality: An assessment of nationwide health and economic impacts in China.

Heatwaves with unprecedented conditions have devastating health impacts. The summer of 2017 saw unusual heat in China and other regions on earth. Although epidemiologic evidence is clear for elevated mortality risks of heatwaves, the economic impacts due to heatwave-associated mortality remain poorly characterized. Hence, this study systematically assessed the mortality and economic impacts of the 2017 exceptional heatwaves in China. We first used the generalized linear mixed-effect model with Poisson distribution to examine the mortality risks of the 2017 heatwaves in 91 Chinese counties. Further, we calculated the excess deaths attributable to heatwaves in 2852 counties. Finally, we evaluated the city- and province-level death-related economic burden of the 2017 heatwaves based on the value of statistical life (VSL). We found that the 2017 exceptional heatwaves had a statistically significant association (relative risk was 1.23, 95% confidence interval 1.14-1.32) with all-cause mortality across 91 Chinese counties. Nationwide, a total of 16,299 all-cause deaths that occurred in 2017 were attributable to the exceptional heatwaves, resulting in an overall death-related economic loss of 61,304 million RMB as valued by VSL. Given that extraordinary heatwaves are projected to be more frequent under global climate change, our findings could enhance the current understanding of heatwaves' health and economic impacts and add valuable insights in projection studies of estimating the future health burden of heatwaves.

Tropical Cyclone Exposures and Risks of Emergency Medicare Hospital Admission for Cardiorespiratory Diseases in 175 Urban United States Counties, 1999-2010.

BACKGROUND: Although injuries experienced during hurricanes and other tropical cyclones have been relatively well-characterized through traditional surveillance, less is known about tropical cyclones' impacts on noninjury morbidity, which can be triggered through pathways that include psychosocial stress or interruption in medical treatment. METHODS: We investigated daily emergency Medicare hospitalizations (1999-2010) in 180 US counties, drawing on an existing cohort of high-population counties. We classified counties as exposed to tropical cyclones when storm-associated peak sustained winds were ≥21 m/s at the county center; secondary analyses considered other wind thresholds and hazards. We matched storm-exposed days to unexposed days by county and seasonality. We estimated change in tropical cyclone-associated hospitalizations over a storm period from 2 days before to 7 days after the storm's closest approach, compared to unexposed days, using generalized linear mixed-effect models. RESULTS: For 1999-2010, 175 study counties had at least one tropical cyclone exposure. Cardiovascular hospitalizations decreased on the storm day, then increased following the storm, while respiratory hospitalizations were elevated throughout the storm period. Over the 10-day storm period, cardiovascular hospitalizations increased 3% (95% confidence interval = 2%, 5%) and respiratory hospitalizations increased 16% (95% confidence interval = 13%, 20%) compared to matched unexposed periods. Relative risks varied across tropical cyclone exposures, with strongest association for the most restrictive wind-based exposure metric. CONCLUSIONS: In this study, tropical cyclone exposures were associated with a short-term increase in cardiorespiratory hospitalization risk among the elderly, based on a multi-year/multi-site investigation of US Medicare beneficiaries ≥65 years.

The Shape of the Concentration-Response Association between Fine Particulate Matter Pollution and Human Mortality in Beijing, China, and Its Implications for Health Impact Assessment.

BACKGROUND: Studies found approximately linear short-term associations between particulate matter (PM) and mortality in Western communities. However, in China, where the urban PM levels are typically considerably higher than in Western communities, some studies suggest nonlinearity in this association. Health impact assessments (HIA) of PM in China have generally not incorporated nonlinearity in the concentration-response (C-R) association, which could result in large discrepancies in estimates of excess deaths if the true association is nonlinear. OBJECTIVES: We investigated nonlinearity in the C-R associations between with PM with aerodynamic diameter [Formula: see text] ([Formula: see text]) and mortality in Beijing, China, and the sensitivity of HIA to linearity assumptions. METHODS: We modeled the C-R association between [Formula: see text] and cause-specific mortality in Beijing, China (2009-2012), using generalized linear models (GLM). [Formula: see text] was included through either linear, piecewise-linear, or spline functions to investigate evidence of nonlinearity. To determine the sensitivity of HIA to linearity assumptions, we estimated [Formula: see text]-attributable deaths using both linear- and nonlinear-based C-R associations between [Formula: see text] and mortality. RESULTS: We found some evidence that, for nonaccidental and circulatory mortality, the shape of the C-R association was relatively flat at lower concentrations of [Formula: see text], but then had a positive slope at higher concentrations, indicating nonlinearity. Conversely, the shape for respiratory mortality was positive and linear at lower concentrations of [Formula: see text], but then leveled off at the higher concentrations. Estimates of excess deaths attributable to short-term [Formula: see text] exposure were, in some cases, very sensitive to the linearity assumption in the association, but in other cases robust to this assumption. CONCLUSIONS: Our results demonstrate some evidence of nonlinearity in [Formula: see text]-mortality associations and that an assumption of linearity in this association can influence HIAs, highlighting the importance of understanding potential nonlinearity in the [Formula: see text]-mortality association at the high concentrations of [Formula: see text] in developing megacities like Beijing. https://doi.org/10.1289/EHP4464.