Life Course Air Pollution Exposure and Cognitive Decline: Modelled Historical Air Pollution Data and the Lothian Birth Cohort 1936.

BACKGROUND: Air pollution has been consistently linked with dementia and cognitive decline. However, it is unclear whether risk is accumulated through long-term exposure or whether there are sensitive/critical periods. A key barrier to clarifying this relationship is the dearth of historical air pollution data. OBJECTIVE: To demonstrate the feasibility of modelling historical air pollution data and using them in epidemiologicalmodels. METHODS: Using the EMEP4UK atmospheric chemistry transport model, we modelled historical fine particulate matter (PM2.5) concentrations for the years 1935, 1950, 1970, 1980, and 1990 and combined these with contemporary modelled data from 2001 to estimate life course exposure in 572 participants in the Lothian Birth Cohort 1936 with lifetime residential history recorded. Linear regression and latent growth models were constructed using cognitive ability (IQ) measured by the Moray House Test at the ages of 11, 70, 76, and 79 years to explore the effects of historical air pollution exposure. Covariates included sex, IQ at age 11 years, social class, and smoking. RESULTS: Higher air pollution modelled for 1935 (when participants would have been in utero) was associated with worse change in IQ from age 11-70 years (ß = -0.006, SE = 0.002, p = 0.03) but not cognitive trajectories from age 70-79 years (p > 0.05). There was no support for other critical/sensitive periods of exposure or an accumulation of risk (all p > 0.05). CONCLUSION: The life course paradigm is essential in understanding cognitive decline and this is the first study to examine life course air pollution exposure in relation to cognitive health.

Associations among particulate matter, hazardous air pollutants and methane emissions from the Aliso Canyon natural gas storage facility during the 2015 blowout.

In October of 2015, a large underground storage well at the Aliso Canyon natural gas storage facility experienced a massive methane leak (also referred to as "natural gas blowout"), which resulted in the largest ever anthropogenic release of methane from a single point source in the United States. Additional sampling conducted during the event revealed unique gas and particle concentrations in ambient air and a characteristic "fingerprint" of metals in the indoor dust samples similar to samples taken at the blowout site. We further investigated the association between the Aliso Canyon natural gas storage site and several measured air pollutants by: (a) conducting additional emission source studies using meteorological data and correlations between particulate matter, methane, and hazardous air pollutants (HAPs) collected during the natural gas blowout at distances ranging from 1.2 to 7.3 km due south of well SS25, (b) identifying the unique i/n-pentane ratio signature associated with emissions from the blowout event, and (c) identifying characteristics unique to the homes that tested positive for air pollutants using data collected from extensive indoor environmental assessment surveys. Results of air quality samples collected near Aliso Canyon during the final weeks of the event revealed that elevated levels of several HAP compounds were likely influenced by the active natural gas blowout. Furthermore, the final attempts to plug the well during the days preceding the well kill were associated with particle emissions likely from the well site. Together, this investigation suggests uncontrolled leaks or blowout events at natural gas storage facilities have the potential to release harmful pollutants with adverse health and environmental consequences into proximate communities. With this evidence, our recommendations include facility-specific meteorological and air quality data-collection equipment installed at natural gas storage facilities and support of environmental surveillance after severe off-normal operation events.

Satellite-derived PM2.5 concentration trends over Eastern China from 1998 to 2016: Relationships to emissions and meteorological parameters.

Fine particulate matter (PM2.5) pollution in Eastern China (EC) has raised concerns due to its adverse effects on air quality, climate, and human health. This study investigated the long-term variation trend in satellite-derived PM2.5 concentrations and how it was related to pollutant emissions and meteorological parameters over EC and seven regions of interest (ROIs) during 1998-2016. Over EC, the annual mean PM2.5 increased before 2006 due to the enhanced emissions of primary PM2.5, NOx and SO2, but decreased with the reduced SO2 emissions after 2006 evidently in response to China's clean air policies. In addition, results from statistical analyses indicated that in the North China Plain (NCP), Northeast China (NEC), Sichuan Basin (SCB) and Central China (CC) planetary boundary layer height (PBLH) was the dominant meteorological driver for the PM2.5 decadal changes, and in the Pearl River Delta (PRD) wind speed is the leading factor. Overall, the variation in meteorological parameters accounted for 48% of the variances in PM2.5 concentrations over EC. The population-weighted PM2.5 over EC increased from 36.4 µg/m3 in 1998-2004 (P1) to 49.4 µg/m3 in 2005-2010 (P2) then decreased to 46.5 µg/m3 in 2011-2016 (P3). In the NCP and NEC, the percentages of the population living above the World Health Organization (WHO) Interim Target-1 (IT-1, 35 µg/m3) have risen steadily over the past 20 yr, reaching maxima of 97.3% and 78.8% in P3, respectively, but decreases of ∼30% from P2 to P3 were found for the SCB and PRD.

A chronology of ratios between black smoke and PM10 and PM2.5 in the context of comparison of air pollution epidemiology concentration-response functions.

BACKGROUND: For many air pollution epidemiological studies in Europe, 'black smoke' (BS) was the only measurement available to quantify ambient particulate matter (PM), particularly for exposures prior to the mid-1990s when quantification via the PM10 and/or PM2.5 metrics was introduced. The aim of this work was to review historic BS and PM measurements to allow comparison of health concentration-response functions (CRF) derived using BS as the measure of exposure with CRFs derived using PM10 or PM2.5. METHODS: The literature was searched for quantitative information on measured ratios of BS:PM10, BS:PM2.5, and chemical composition of PM; with specific focus on the United Kingdom (UK) between 1970 and the early 2000s when BS measurements were discontinued. RESULTS: The average BS:PM10 ratio in urban background air was just below unity at the start of the 1970s, decreased rapidly to ≈ 0.7 in the mid-1970s and to ≈ 0.5 at the end of the 1970s, with continued smaller declines in the 1980s, and was within the range 0.2-0.4 by the end of the 1990s. The limited data for the BS:PM2.5 ratio suggest it equalled or exceeded unity at the start of the 1970s, declined to ≈ 0.7 by the end of the 1970s, with slower decline thereafter to a range 0.4-0.65 by the end of the 1990s. For an epidemiological study that presents a CRF BS value, the corresponding CRF PM10 value can be estimated as R BS:PM10 × CRF BS where R BS:PM10 is the BS:PM10 concentration ratio, if the toxicity of PM10 is assumed due only to the component quantified by a BS measurement. In the general case of some (but unknown) contribution of toxicity from non-BS components of PM10 then CRF PM10 > R BS:PM10 × CRF BS, with CRF PM10 exceeding CRFBS if the toxicity of the other components in PM10 is greater than the toxicity of the component to which the BS metric is sensitive. Similar analyses were applied to relationships between CRF PM2.5 and CRF BS. CONCLUSIONS: Application of this analysis to example published CRF BS values for short and long-term health effects of PM suggest health effects from other components in the PM mixture in addition to the fine black particles characterised by BS.

Historic air pollution exposure and long-term mortality risks in England and Wales: prospective longitudinal cohort study.

INTRODUCTION: Long-term air pollution exposure contributes to mortality but there are few studies examining effects of very long-term (>25 years) exposures. METHODS: This study investigated modelled air pollution concentrations at residence for 1971, 1981, 1991 (black smoke (BS) and SO2) and 2001 (PM10) in relation to mortality up to 2009 in 367,658 members of the longitudinal survey, a 1% sample of the English Census. Outcomes were all-cause (excluding accidents), cardiovascular (CV) and respiratory mortality. RESULTS: BS and SO2 exposures remained associated with mortality decades after exposure-BS exposure in 1971 was significantly associated with all-cause (OR 1.02 (95% CI 1.01 to 1.04)) and respiratory (OR 1.05 (95% CI 1.01 to 1.09)) mortality in 2002-2009 (ORs expressed per 10 µg/m(3)). Largest effect sizes were seen for more recent exposures and for respiratory disease. PM10 exposure in 2001 was associated with all outcomes in 2002-2009 with stronger associations for respiratory (OR 1.22 (95% CI 1.04 to 1.44)) than CV mortality (OR 1.12 (95% CI 1.01 to 1.25)). Adjusting PM10 for past BS and SO2 exposures in 1971, 1981 and 1991 reduced the all-cause OR to 1.16 (95% CI 1.07 to 1.26) while CV and respiratory associations lost significance, suggesting confounding by past air pollution exposure, but there was no evidence for effect modification. Limitations include limited information on confounding by smoking and exposure misclassification of historic exposures. CONCLUSIONS: This large national study suggests that air pollution exposure has long-term effects on mortality that persist decades after exposure, and that historic air pollution exposures influence current estimates of associations between air pollution and mortality.

Evaluation of historical beryllium abundance in soils, airborne particulates and facilities at Lawrence Livermore National Laboratory.

Beryllium has been historically machined, handled and stored in facilities at Lawrence Livermore National Laboratory (LLNL) since the 1950s. Additionally, outdoor testing of beryllium-containing components has been performed at LLNL's Site 300 facility. Beryllium levels in local soils and atmospheric particulates have been measured over three decades and are comparable to those found elsewhere in the natural environment. While localized areas of beryllium contamination have been identified, laboratory operations do not appear to have increased the concentration of beryllium in local air or water. Variation in airborne beryllium correlates to local weather patterns, PM10 levels, normal sources (such as resuspension of soil and emissions from coal power stations) but not to LLNL activities. Regional and national atmospheric beryllium levels have decreased since the implementation of the EPA's 1990 Clean-Air-Act. Multi-element analysis of local soil and air samples allowed for the determination of comparative ratios for beryllium with over 50 other metals to distinguish between natural beryllium and process-induced contamination. Ten comparative elemental markers (Al, Cs, Eu, Gd, La, Nd, Pr, Sm, Th and Tl) that were selected to ensure background variations in other metals did not collectively interfere with the determination of beryllium sources in work-place samples at LLNL. Multi-element analysis and comparative evaluation are recommended for all workplace and environmental samples suspected of beryllium contamination. The multi-element analyses of soils and surface dusts were helpful in differentiating between beryllium of environmental origin and beryllium from laboratory operations. Some surfaces can act as "sinks" for particulate matter, including carpet, which retains entrained insoluble material even after liquid based cleaning. At LLNL, most facility carpets had beryllium concentrations at or below the upper tolerance limit determined by sampling facilities with no history of beryllium work. Some facility carpets had beryllium concentrations above the upper tolerance limits but can be attributed to tracking of local soils, while other facilities showed process-induced contamination from adjacent operations. In selected cases, distinctions were made as to the source of beryllium in carpets. Guidance on the determination of facility beryllium sources is given.

Health effects research and regulation of diesel exhaust: an historical overview focused on lung cancer risk.

The mutagenicity of organic solvent extracts from diesel exhaust particulate (DEP), first noted more than 55 years ago, initiated an avalanche of diesel exhaust (DE) health effects research that now totals more than 6000 published studies. Despite an extensive body of results, scientific debate continues regarding the nature of the lung cancer risk posed by inhalation of occupational and environmental DE, with much of the debate focused on DEP. Decades of scientific scrutiny and increasingly stringent regulation have resulted in major advances in diesel engine technologies. The changed particulate matter (PM) emissions in "New Technology Diesel Exhaust (NTDE)" from today's modern low-emission, advanced-technology on-road heavy-duty diesel engines now resemble the PM emissions in contemporary gasoline engine exhaust (GEE) and compressed natural gas engine exhaust more than those in the "traditional diesel exhaust" (TDE) characteristic of older diesel engines. Even with the continued publication of epidemiologic analyses of TDE-exposed populations, this database remains characterized by findings of small increased lung cancer risks and inconsistent evidence of exposure-response trends, both within occupational cohorts and across occupational groups considered to have markedly different exposures (e.g. truckers versus railroad shopworkers versus underground miners). The recently published National Institute for Occupational Safety and Health (NIOSH)-National Cancer Institute (NCI) epidemiologic studies of miners provide some of the strongest findings to date regarding a DE-lung cancer association, but some inconsistent exposure-response findings and possible effects of bias and exposure misclassification raise questions regarding their interpretation. Laboratory animal studies are negative for lung tumors in all species, except for rats under lifetime TDE-exposure conditions with durations and concentrations that lead to "lung overload." The species specificity of the rat lung response to overload, and its occurrence with other particle types, is now well-understood. It is thus generally accepted that the rat bioassay for inhaled particles under conditions of lung overload is not predictive of human lung cancer hazard. Overall, despite an abundance of epidemiologic and experimental data, there remain questions as to whether TDE exposure causes increased lung cancers in humans. An abundance of emissions characterization data, as well as preliminary toxicological data, support NTDE as being toxicologically distinct from TDE. Currently, neither epidemiologic data nor animal bioassay data yet exist that directly bear on NTDE carcinogenic potential. A chronic bioassay of NTDE currently in progress will provide data on whether NTDE poses a carcinogenic hazard, but based on the significant reductions in PM mass emissions and the major changes in PM composition, it has been hypothesized that NTDE has a low carcinogenic potential. When the International Agency for Research on Cancer (IARC) reevaluates DE (along with GEE and nitroarenes) in June 2012, it will be the first authoritative body to assess DE carcinogenic health hazards since the emergence of NTDE and the accumulation of data differentiating NTDE from TDE.

A short history of the toxicology of inhaled particles.

Particle toxicology arose in order to understand the mechanisms of adverse effects of 3 major particle types that had historically exerted the greatest toll of ill-health--quartz, coal and asbestos. By the middle of the last century rat inhalation studies had been carried out and the pathology documented, but true mechanistic particle toxicology did not really take off until the 1970s when cell culture techniques became available. By the 1980s glass fibres were a major focus of interest and attempts to develop a structure-toxicity paradigm centred on biopersistence. In the 1990s environmental particles dominated the particle toxicology agenda and the cardiovascular system emerged as a target for inhaled particles, raising new challenges for particle toxicologists. We are currently in the era of nanotoxicology where a large and diverse range of new nanoparticles types are under scrutiny.

Health effects of nanomaterials.

With the rapid growth of nanotechnology and future bulk manufacture of nanomaterials comes the need to determine, understand and counteract any adverse health effects of these materials that may occur during manufacture, during use, or accidentally. Nanotechnology is expanding rapidly and will affect many aspects of everyday life; there are already hundreds of products that utilize nanoparticles. Paradoxically, the unique properties that are being exploited (e.g. high surface reactivity and ability to cross cell membranes) might have negative health impacts. The rapid progress in development and use of nanomaterials is not yet matched by toxicological investigations. Epidemiological studies implicate the ultrafine (nano-sized) fraction of particulate air pollution in the exacerbation of cardiorespiratory disease and increased morbidity. Experimental animal studies suggest that the increased concentration of nanoparticles and higher reactive surface area per unit mass, alongside unique chemistry and functionality, is important in the acute inflammatory and chronic response. Some animal models have shown that nanoparticles which are deposited in one organ (e.g. lung and gut) may access the vasculature and target other organs (e.g. brain and liver). The exact relationship between the physicochemistry of a nanoparticle, its cellular reactivity, and its biological and systemic consequences cannot be predicted. It is important to understand such relationships to enjoy the benefits of nanotechnology without being exposed to the hazards.

Historical perspective of heavy metals contamination (Cd, Cr, Cu, Hg, Pb, Zn) in the Seine River basin (France) following a DPSIR approach (1950-2005).

The Driver-Pressures-State-Impact-Response approach is applied to heavy metals in the Seine River catchment (65,000 km(2); 14 million people of which 10 million are aggregated within Paris megacity; 30% of French industrial and agricultural production). The contamination pattern at river mouth is established on the particulate material at different time scales: 1930-2000 for floodplain cores, 1980-2003 for suspended particulate matter (SPM) and bed-sediments, 1994-2003 for atmospheric fallout and annual flood deposits. The Seine has been among the most contaminated catchments with maximum contents recorded at 130 mg kg(-1) for Cd, 24 for Hg, 558 for Pb, 1620 for Zn, 347 for Cu, 275 for Cr and 150 for Ni. Today, the average levels for Cd (1.8 mg kg(-1)), Hg (1.08), Pb (108), Zn (370), Cu (99), Cr (123) and Ni (31) are much lower but still in the upper 90% of the global scale distribution (Cr and Ni excepted) and well above the natural background values determined on pre-historical deposits. All metal contents have decreased at least since 1955/65, well before metal emission regulations that started in the mid 1970's and the metal monitoring in the catchment that started in the early 1980's. In the last 20 y, major criteria changes for the management of contaminated particulates (treated urban sludge, agricultural soils, dredged sediments) have occurred. In the mid 1990's, there was a complete shift in the contamination assessment scales, from sediment management and water usage criteria to the good ecological state, now required by the 2000 European Directive. When comparing excess metal outputs, associated to river SPM, to the average metal demand within the catchment from 1950 to 2000, the leakage ratios decrease exponentially from 1950 to 2000 for Cd, Cr, Cu, Pb and Zn, meanwhile, a general increase of the demand is observed: the rate of recycling and/or treatment of metals within the anthroposphere has been improved ten-fold. Hg environmental trajectory is very specific: there is a marked decontamination from 1970 to 2000, but the leakage ratio remains very high (10 to 20%) during this period. Drivers and Pressures are poorly known prior to 1985; State evolution since 1935 has been reconstructed from flood plain cores analysis; Impacts were maximum between 1950 and 1970 but remained unknown due to analytical limitation and lack of awareness. Some Responses are lagging 10 y behind monitoring and have much evolved in the past 10 y.