Atmospheric metal deposition in a moss data correlation study with mortality and disease in the Netherlands

Métaux, pollution de l’air et santé

L’exposition à long terme aux particules atmosphériques a des effets bien documentés sur la santé humaine, mais le rôle des métaux reste à explorer. En France, la réglementation impose le suivi des teneurs ambiantes de certains métaux. Mais ces données, du fait d’un maillage trop large ou irrégulier, sont difficilement exploitables en épidémiologie à grande échelle. Les mousses, des végétaux capables d’accumuler les métaux atmosphériques, sont utilisées depuis plusieurs décennies en biosurveillance de la qualité de l’air. Elles fournissent des données exploitables en épidémiologie grâce auxquelles nous avons montré une association entre métaux d’origine anthropique et sur-risque de mortalité en France.

Long-term exposure to atmospheric metals assessed by mosses and mortality in France

BACKGROUND

Long-term exposure to air pollution affects health, but little is known about exposure to atmospheric metals. Estimating exposure to atmospheric metals across large spatial areas remains challenging. Metal concentrations in mosses could constitute a useful proxy. Here, we linked moss biomonitoring and epidemiological data to investigate the associations between long-term exposure to metals and mortality.

METHODS

We modelled and mapped 13 atmospheric metals from a 20-year national moss biomonitoring program to derive exposure estimates across France. In the population-based Gazel cohort, we included 11,382 participants from low to intermediate population density areas and assigned modelled metals to their residential addresses. We distinguished between airborne metals that are primarily of natural origin and those primarily of anthropogenic origin. Associations were estimated between exposure to metals and mortality (natural-cause, cardiovascular and respiratory), using Cox models, with confounder adjustment at individual level.

FINDINGS

Between 1996 and 2017, there were 1313 deaths in the cohort (including 181 cardiovascular and 33 respiratory). Exposure to the anthropogenic metals was associated with an increased risk of natural-cause mortality (hazard ratio of 1.16 [1.08-1.24] per interquartile range of exposure), while metals from natural sources were not.

INTERPRETATION

Some atmospheric anthropogenic metals may be associated with excess mortality - even in areas with relatively low levels of exposure to air pollution. Consistent with the previous literature, our findings support the use of moss biomonitoring as a tool to assess health effects of air pollution exposure at individual level.

Active moss biomonitoring for extensive screening of urban air pollution: Magnetic and chemical analyses

In this study, active magnetic biomonitoring of moss for particulate air pollution and an assessment of heavy metals and polycyclic aromatic hydrocarbons (PAHs) were performed for the entire metropolitan area of Belgrade. Two mosses, Sphagnum girgensohnii (a species of the most recommended biomonitoring moss genus) and Hypnum cupressiforme (a common moss in the study area), were used. During the summer of 2013, moss bags were exposed at 153 sampling sites, forming a dense network of sites. A type II regression model was applied to test the interchangeable use of the two moss species. Significantly higher levels of all measured pollutants were recorded by S. girgensohnii in comparison with H. cupressiforme. Based on the results, the mosses could not be interchangeably used in urban areas, except for the biomonitoring of Cu. Nevertheless, according to the relative accumulation factors obtained for both moss species, similar city zones related to high, moderate and low levels of air pollution were distinguished. Moreover, new pollution hotspots, omitted by regulatory monitoring, were identified. The results demonstrate that moss magnetic analysis represents an effective first step for obtaining an overview of particulate air pollution before more expensive chemical analyses. Active moss biomonitoring could be applied as a pragmatic approach for optimizing the representativeness of regulatory monitoring networks.

Biomonitoring persistent organic pollutants in the atmosphere with mosses: performance and application

Persistent organic pollutants (POPs) have aroused environmentalists and public concerns due to their toxicity, bioaccumulation and persistency in the environment. However, monitoring atmospheric POPs using conventional instrumental methods is difficult and expensive, and POP levels in air samples represent an instantaneous value at a sampling time. Biomonitoring methods can overcome this limitation, because biomonitors can accumulate POPs, serve as long-term integrators of POPs and provide reliable information to assess the impact of pollutants on the biota and various ecosystems. Recently, mosses are increasingly employed to monitor atmospheric POPs. Mosses have been applied to indicate POP pollution levels in the remote continent of Antarctica, trace distribution of POPs in the vicinity of pollution sources, describe the spatial patterns at the regional scale, and monitor the changes in the pollution intensity along time. In the future, many aspects need to be improved and strengthened: (i) the relationship between the concentrations of POPs in mosses and in the atmosphere (different size particulates and vapor phases); and (ii) the application of biomonitoring with mosses in human health studies.

[Air pollution biomonitoring with plants and fungi: concepts and uses]

Air pollution remains a major environmental concern of the French. Since about 30 years, due to evolution and diversification of sources, pollution became more and more complex, constituting a true "cocktail". Today, it is very important to know environmental and health effects of this cocktail. In this context air biomonitoring using plants and fungi can bring a lot of information. Biomonitoring includes four concepts: the use of biomarkers, bioindication biointegration and bioaccumulation. These four concepts are articulated according to the levels of biological organization, what links up biosurveillance on fundamental plan with ecotoxicology. It is a complementary approach of the physicochemical techniques of air pollution measurements. The main objectives of biomonitoring studies are the monitoring of the space and temporal distribution of pollutants effect; the monitoring of local sources; participation in the health risks assessment; the information of people and the help to decision in public policies. Biomonitoring of air quality is a method, which made its proof in numerous domains of application and brings fundamental information on the impacts of the quality of air. Recent evolution of low concerning biggest industries allows us to envisage the increase of air quality biomonitoring with plants and fungi applications in the field of the valuation of environmental and health risks. The recent normalization (French and European) of different methods will also allow the development of uses.

Is there a future for biomonitoring of elemental air pollution? A review focused on a larger-scaled health-related (epidemiological) context

The present paper focuses on biomonitoring of elemental atmospheric pollution, which is reviewed in terms of larger-scaled biomonitoring surveys in an epidemiological context. Based on the literature information, today's availability of solar-powered small air filter samplers and fibrous ion exchange materials is regarded as adequate or an even better alternative for biomonitor transplant materials used in small-scaled set-ups, but biomonitors remain valuable in larger-scaled set-ups and in unforeseen releases and accidental situations. In the latter case, in-situ biomonitoring is seen as the only option for a retrospective study: biomoniors are there before one even knows that they are needed. For biomonitoring, nuclear analytical techniques are discussed as key techniques, especially because of the necessary multi-element assessments in both source recognition and single-element interpretation. To live up to the demands in an epidemiological context, larger-scaled in-situ biomonitoring asks for large numbers of samples, and consequently, for large total sample masses, this all to ensure representation of both local situations and survey area characteristics. Possibly, this point should direct studies into new "easy-to-sample" biomonitor organisms, of which high masses and numbers may be obtained in field work, rather than continue with biomonitors such as lichens. This also means that both sample handling and processing are of key importance in these studies. To avoid problems in comparability of analytical general procedures in milling, homogenization and digestion of samples of large masses, the paper proposes to involve only few but high-quality laboratories in the total element assessment routines. In this respect, facilities that can handle large sample masses in the assessment of element concentrations are to be preferred. This all highlights the involvement of large-sample-volume nuclear facilities, which, however, should be upgraded and automated in their operation to ensure the necessary sample throughput in larger-scaled biomonitoring.

Heavy metal deposition in the Italian "triangle of death" determined with the moss Scorpiurum circinatum

In this study, a biomonitoring project using the moss Scorpiurum circinatum was carried out to evaluate the deposition and biological effects of heavy metals in the area of Acerra (Naples, S Italy), one of the vertices of the sadly called "Italian triangle of death" owing to the dramatic increase in tumours. The results clearly indicated that the study area is heavily polluted by heavy metals, a large proportion of which is likely present in the atmosphere in particulate form. The ultrastructural organization of exposed samples was essentially preserved, but cell membrane pits, cytoplasm vesicles and concentric multilamellar/multivesicular bodies, probably induced by pollution, were found, which may be involved in the tolerance mechanisms to metal pollution in this moss species. Although severe biological effects were not found at the ultrastructural level in the exposed moss, effects on humans, especially after long-term exposure, are to be expected.

Correlating element atmospheric deposition and cancer mortality in Portugal: data handling and preliminary results

This study, framed within geographical epidemiology, presents preliminary findings concerning the association between the concentrations of chemical elements obtained through atmospheric biomonitoring with lichens and cancer mortality in the Portuguese population. Exploratory analyses were performed to identify potential confounders for the relationships between chemical elements and neoplasm mortality and to assess the extent of their interference. The results of this study highlight some methodological and conceptual difficulties inherent to observational and geographical studies, in the specific context of the Portuguese population, and the challenge posed by the large numbers of pollutants considered.

Detection of exposition risk to arsenic in Portugal assessed by air deposition in biomonitors and water contamination

Human exposure risk to environmental arsenic is evaluated by combining drinking water and atmospheric deposition, assessed tap water analysis and a moss biomonitoring survey. Water analyses are assessed through mandatory national and European regulations for the supplying areas. Moss concentrations were determined as part of a biomonitoring survey performed at a national level in 2002. For each of the parameters, continuous maps of indicator values were determined applying geostatistical methods, namely indicator kriging. The exposure risk of human populations was determined afterwards combining the indicator values of water and biomonitoring values. The identified regions of accumulated water and atmospheric exposure are in the inland north and central areas of the country.

Atmospheric lead fallout over the last century recorded in Gulf of Lions sediments (Mediterranean Sea)

Six marine sediment cores from the Gulf of Lions continental slope (700-1700 m water depth) were analyzed for stable lead isotopes and (210)Pb geochronology in order to reconstruct lead atmospheric fallout pattern during the last century. The detrital lead contribution is 25 microg g(-1) and the mean sediment anthropogenic inventory is 110+/-7 microg cm(-2), a little bit higher than atmospheric deposition estimate. Anthropogenic lead accumulation in sediments peaked in early 1970s (1973+/-2) in agreement with lead emissions features. For the period 1986-1997, the sediment signal also reflect the decrease of atmospheric lead described by independent atmospheric fallout investigations. The anthropogenic Pb deposition in the late 1990s was similar to the 1950s deposition, attesting thus of the output of European environmental policies.

Moss (Bryum radiculosum) as a bioindicator of trace metal deposition around an industrialised area in Sardinia (Italy)

The moss Bryum radiculosum (Brid.), a species typical of dry and coastal environments, was used as a bioindicator for the estimation of atmospheric trace metal deposition around the industrial site of Portoscuso (Sardinia, Italy), which includes a lead-zinc smelter, two power plants, and aluminium production factories. For Cd, Pb, Zn, and V the results showed very similar patterns with extremely high values in the immediate surroundings of the industrial area. Copper and Cr showed somewhat different patterns, but still pointing to local pollution sources. The levels of metals at distance of about 13 km from the industrial site were still higher than in background samples. In order to evaluate the suitability of B. radiculosum for monitoring studies, trace metal concentrations in moss were compared with bulk deposition measurements in the same area. Correlation was significant only for Pb, Cd, and Zn. For Cr, Cu, and V the results showed high variability, mainly to be ascribed to soil factors.