PM10 Chemical Profile during North African Dust Episodes over French West Indies

The French West Indies are periodically affected by North African dust episodes (NADE) resulting in PM10 concentrations exceeding air quality standards. The aim of the present study was to decipher the PM10 chemical profile during NADE over Guadeloupe. PM10 samples were collected daily at a rural site and an urban site during five episodes between April and October in 2017. During these events, the median PM10 mass concentrations were, on average, 2 to 5 times higher than in the post-episode baseline period. Sampled filters were analyzed for their quantification of chemical constituents including carbonaceous fractions (elemental and organic carbon, EC/OC), anions/cations and levoglucosan, 51 elements, and 57 selected organic species. An orthogonal partial least squares discriminant analysis (OPLS-DA) was conducted to identify the specific chemical profile of PM10 during NADE: 16 elements were identified as the most discriminant between the NADE and the control samples with mass concentration levels twice as high during a NADE. Among them, only two (Mn and V) are classified as emerging pollutant while no limit values exist for the other ones. The extensive characterization of the NADE PM10 chemical profile we performed is a key step to assess the chemical exposure of French West Indies populations during such events.

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Cellulose in atmospheric particulate matter

10.5194/acp-2021-930 ◽

2021 ◽

Author(s):

Adam Matthew Brighty ◽

Véronique Jacob ◽

Gaëlle Uzu ◽

Lucille Borlaza ◽

Sebastien Conil ◽

...

Keyword(s):

Ambient Air ◽

Atmospheric Particulate Matter ◽

Carbonaceous Aerosol ◽

Rural Site ◽

Urban Site ◽

Plant Debris ◽

Specific Chemical ◽

Chemical Tracers ◽

Plant Matter ◽

Urban Sites

Abstract. The spatiotemporal variations of free cellulose concentrations in atmospheric particles, as a proxy for plant debris, were investigated using a novel HPLC-PAD method. Filter samples were taken from nine sites of varying characteristics across France and Switzerland, with sampling covering all seasons. Concentrations of cellulose, as well as carbonaceous aerosol and other source-specific chemical tracers (e.g. Elemental Carbon (EC), levoglucosan, polyols, trace metals, and glucose) were quantified. Annual mean free cellulose concentrations within PM10 ranged from 29 ± 38 ng m−3 at Bern (urban site) to 284 ± 225 ng m−3 at Payerne (rural site). Concentrations were considerably higher during episodes, with spikes exceeding 1150 and 2200 ng m−3 at Payerne and ANDRA-OPE (rural site), respectively. A clear seasonality, with highest cellulose concentrations during summer and autumn, was observed at all rural and some urban sites. However, some urban locations exhibited a weakened seasonality. Contributions of cellulose-carbon to total organic carbon are moderate on average (0.7–5.9 %), but much greater during ‘episodes’, reaching close to 20 % at Payerne. Cellulose concentrations correlated poorly between sites, even a ranges of about 10 km, indicating the localised nature of the sources of atmospheric plant debris. With regards to these sources, correlations between cellulose and typical biogenic chemical tracers (polyols and glucose) were moderate to strong (Rs 0.28−0.78, p < 0.0001) across the nine sites. Seasonality was strongest at sites with stronger biogenic correlations, suggesting the main source of cellulose arises from biogenic origins. A second input to ambient plant debris concentrations was suggested via resuspension of plant matter at several urban sites, due to moderate cellulose correlations with mineral dust tracers, Ca2+ and Ti metal (Rs 0.28−0.45, p < 0.007). No correlation was obtained with the biomass burning tracer (levoglucosan), an indication that this is not a source of atmospheric cellulose. Finally, an investigation into the interannual variability of atmospheric cellulose across the Grenoble metropole area was completed. It was shown that concentrations and sources of ambient cellulose can vary considerably between years. All together, these results deeply improve our knowledge on the phenomenology of plant debris within ambient air.

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Estimation of Particulate Matter Contributions from Desert Outbreaks in Mediterranean Countries (2015–2018) Using the Time Series Clustering Method

Atmosphere ◽

10.3390/atmos12010005 ◽

2020 ◽

Vol 12 (1) ◽

pp. 5

Author(s):

Álvaro Gómez-Losada ◽

José C. M. Pires

Keyword(s):

Time Series ◽

World Health ◽

North African ◽

Clustering Method ◽

Time Series Clustering ◽

Average Characteristic ◽

Limit Values ◽

African Dust ◽

Pm10 And Pm2.5 ◽

Mediterranean Countries

North African dust intrusions can contribute to exceedances of the European PM10 and PM2.5 limit values and World Health Organisation standards, diminishing air quality, and increased mortality and morbidity at higher concentrations. In this study, the contribution of North African dust in Mediterranean countries was estimated using the time series clustering method. This method combines the non-parametric approach of Hidden Markov Models for studying time series, and the definition of different air pollution profiles (regimes of concentration). Using this approach, PM10 and PM2.5 time series obtained at background monitoring stations from seven countries were analysed from 2015 to 2018. The average characteristic contributions to PM10 were estimated as 11.6 ± 10.3 µg·m−3 (Bosnia and Herzegovina), 8.8 ± 7.5 µg·m−3 (Spain), 7.0 ± 6.2 µg·m−3 (France), 8.1 ± 5.9 µg·m−3 (Croatia), 7.5 ± 5.5 µg·m−3 (Italy), 8.1 ± 7.0 µg·m−3 (Portugal), and 17.0 ± 9.8 µg·m−3 (Turkey). For PM2.5, estimated contributions were 4.1 ± 3.5 µg·m−3 (Spain), 6.0 ± 4.8 µg·m−3 (France), 9.1 ± 6.4 µg·m−3 (Croatia), 5.2 ± 3.8 µg·m−3 (Italy), 6.0 ± 4.4 µg·m−3 (Portugal), and 9.0 ± 5.6 µg·m−3 (Turkey). The observed PM2.5/PM10 ratios were between 0.36 and 0.69, and their seasonal variation was characterised, presenting higher values in colder months. Principal component analysis enabled the association of background sites based on their estimated PM10 and PM2.5 pollution profiles.

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‘Colonial livery’ and the chemise à la reine, 1779–1784

Costume ◽

10.3366/cost.2018.0069 ◽

2018 ◽

Vol 52 (2) ◽

pp. 217-239 ◽

Cited By ~ 1

Author(s):

Jane Ashelford

Keyword(s):

West Indies ◽

Jane Austen ◽

French West Indies ◽

Cotton Industry ◽

Saint Domingue ◽

Marie Antoinette ◽

White Elite

When Jane Austen wrote in January 1801 that ‘Mrs Powlett was at once expensively and nakedly dressed’, the fashion for muslin dresses had existed for some eighteen years. This article examines the crucial period between 1779 and 1784 when the muslin garment, which became known as the chemise à la reine, was developed and refined. Originating in the French West Indies, the gaulle was the ‘colonial livery’ worn by the wives of the white elite, the ‘grands blancs’, and first appeared as a costume in a ballet performed in Paris in 1779. The version worn by Queen Marie Antoinette in Vigée Le Brun's controversial portrait of 1783 provoked, according to the Baron de Frénilly, ‘a revolution in dress’ which eventually destabilized society. The article focuses on the role played by Saint-Domingue, France's most valuable overseas possession, in the transference of the gaulle from colonial to metropolitan fashion, and how the colony became one of the major providers of unprocessed cotton to the French cotton industry.

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Salt Intake in Nigeria: a nationwide population survey

European Heart Journal ◽

10.1093/ehjci/ehaa946.2866 ◽

2020 ◽

Vol 41 (Supplement_2) ◽

Author(s):

A.N Odili ◽

B.S Chori ◽

B Danladi ◽

P.C Nwakile ◽

J.O Ogedengbe ◽

...

Keyword(s):

Salt Intake ◽

Sodium Intake ◽

Population Analysis ◽

Cost Effective ◽

Rural Site ◽

Urban Site ◽

Funding Source ◽

Salt Reduction ◽

High Salt Intake ◽

The Impact

Abstract Background Population wide salt reduction programmes are cost effective strategies for control of cardiovascular diseases (CVDs). Obtaining a nationwide salt consumption data in a multi-cultural setting as Nigeria's is key for proper implementation and monitoring of such strategy. Methods We measured sodium in 24-hour urine of free-living adult Nigerians selected from an urban and a rural site each from the 6 geopolitical zones of Nigeria to evaluate patterns of salt intake and its associations with blood pressures (BP). Results Across the 12 sites, sodium intake ranged from 97.9 in the rural South-South to 210 mmol/day in the urban site of the same zone. Overall, the median (IQR) daily sodium intake was 143.5 (97.8) mmol; with higher (p=0.0028) levels among the urban 149.7 (113.8) compared to the rural 133.1 (105.2) dwellers. Overall, 20% of the subjects consumed less than the recommended 2g (86mmol) of sodium daily. After adjustment for age, sex and BMI; sodium intake and BP (systolic and diastolic) were positively associated in 8 out of the 12 sites; significantly so in 2 (p<0.05) for systolic. Within population analysis; which included 973 individuals, increasing sodium intake tended (not significantly) to increase SBP but decrease DBP. However, among subjects whose sodium intake was in excess of 257mmol/day, a 100 mmol/day increase in sodium intake was significantly (p=0.04) associated with a 3.3 mmHg increase in SBP. Conclusion Salt intake among Nigerians is higher than the recommended. The impact of sodium intake on BP appears to be evident only among individuals with high salt intake. Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): Wellcome Trust

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A cross-sectional study measuring contact patterns using diaries in an urban and a rural community in South Africa, 2018

BMC Public Health ◽

10.1186/s12889-021-11136-6 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Jackie Kleynhans ◽

Stefano Tempia ◽

Meredith L. McMorrow ◽

Anne von Gottberg ◽

Neil A. Martinson ◽

...

Keyword(s):

South Africa ◽

Age Groups ◽

Cross Sectional Study ◽

Rural Site ◽

Urban Site ◽

Contact Rate ◽

Sectional Study ◽

Cross Sectional ◽

Contact Rates ◽

Contact Patterns

Abstract Background Describing contact patterns is crucial to understanding infectious disease transmission dynamics and guiding targeted transmission mitigation interventions. Data on contact patterns in Africa, especially South Africa, are limited. We measured and compared contact patterns in a rural and urban community, South Africa. We assessed participant and contact characteristics associated with differences in contact rates. Methods We conducted a cross-sectional study nested in a prospective household cohort study. We interviewed participants to collect information on persons in contact with for one day. We described self-reported contact rates as median number people contacted per day, assessed differences in contact rates based on participant characteristics using quantile regression, and used a Poisson model to assess differences in contact rates based on contact characteristics within age groups. We also calculated cumulative person hours in contact within age groups at different locations. Results We conducted 535 interviews (269 rural, 266 urban), with 17,252 contacts reported. The overall contact rate was 14 (interquartile range (IQR) 9–33) contacts per day. Those ≤18 years had higher contact rates at the rural site (coefficient 17, 95% confidence interval (95%CI) 10–23) compared to the urban site, for those aged 14–18 years (13, 95%CI 3–23) compared to < 7 years. No differences were observed for adults. There was a strong age-based mixing, with age groups interacting more with similar age groups, but also interaction of participants of all ages with adults. Children aged 14–18 years had the highest cumulative person hours in contact (116.3 rural and 76.4 urban). Conclusions Age played an important role in the number and duration of contact events, with children at the rural site having almost double the contact rate compared to the urban site. These contact rates can be utilized in mathematical models to assess transmission dynamics of infectious diseases in similar communities.

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Spatial and seasonal variability of PM<sub>2.5</sub> acidity at two Chinese megacities: insights into the formation of secondary inorganic aerosols

Atmospheric Chemistry and Physics ◽

10.5194/acp-12-1377-2012 ◽

2012 ◽

Vol 12 (3) ◽

pp. 1377-1395 ◽

Cited By ~ 105

Author(s):

K. He ◽

Q. Zhao ◽

Y. Ma ◽

F. Duan ◽

F. Yang ◽

...

Keyword(s):

Atmospheric Chemistry ◽

Temporal Variations ◽

Early Summer ◽

Heterogeneous Reactions ◽

Rural Site ◽

Urban Site ◽

Simultaneous Increase ◽

Northwestern Pacific ◽

Inorganic Aerosols ◽

Aerosol Acidity

Abstract. Aerosol acidity is one of the most important parameters influencing atmospheric chemistry and physics. Based on continuous field observations from January 2005 to May 2006 and thermodynamic modeling, we investigated the spatial and seasonal variations in PM2.5 acidity in two megacities in China, Beijing and Chongqing. Spatially, PM2.5 was generally more acidic in Chongqing than in Beijing, but a reverse spatial pattern was found within the two cities, with more acidic PM2.5 at the urban site in Beijing whereas the rural site in Chongqing. Ionic compositions of PM2.5 revealed that it was the higher concentrations of NO3− at the urban site in Beijing and the lower concentrations of Ca2+ within the rural site in Chongqing that made their PM2.5 more acidic. Temporally, PM2.5 was more acidic in summer and fall than in winter, while in the spring of 2006, the acidity of PM2.5 was higher in Beijing but lower in Chongqing than that in 2005. These were attributed to the more efficient formation of nitrate relative to sulfate as a result of the influence of Asian desert dust in 2006 in Beijing and the greater wet deposition of ammonium compared to sulfate and nitrate in 2005 in Chongqing. Furthermore, simultaneous increase of PM2.5 acidity was observed from spring to early summer of 2005 in both cities. This synoptic-scale evolution of PM2.5 acidity was accompanied by the changes in air masses origins, which were influenced by the movements of a subtropical high over the northwestern Pacific in early summer. Finally, the correlations between [NO3−]/[SO42−] and [NH4+]/[SO42−] suggests that under conditions of high aerosol acidity, heterogeneous reactions became one of the major pathways for the formation of nitrate at both cities. These findings provided new insights in our understanding of the spatial and temporal variations in aerosol acidity in Beijing and Chongqing, as well as those reported in other cities in China.

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