Acid Sensitive Sites Research Articles

Impacts of air pollution on human and ecosystem health, and implications for the National Emission Ceilings Directive: Insights from Italy

Across the 28 EU member states there were nearly half a million premature deaths in 2015 as a result of exposure to PM2.5, O3 and NO2. To set the target for air quality levels and avoid negative impacts for human and ecosystems health, the National Emission Ceilings Directive (NECD, 2016/2284/EU) sets objectives for emission reduction for SO2, NOx, NMVOCs, NH3 and PM2.5 for each Member State as percentages of reduction to be reached in 2020 and 2030 compared to the emission levels into 2005. One of the innovations of NECD is Article 9, that mentions the issue of “monitoring air pollution impacts” on ecosystems. We provide a clear picture of what is available in term of monitoring network for air pollution impacts on Italian ecosystems, summarizing what has been done to control air pollution and its effects on different ecosystems in Italy. We provide an overview of the impacts of air pollution on health of the Italian population and evaluate opportunities and implementation of Article 9 in the Italian context, as a case study beneficial for all Member States. The results showed that SO42− deposition strongly decreased in all monitoring sites in Italy over the period 1999–2017, while NO3− and NH4+ decreased more slightly. As a consequence, most of the acid-sensitive sites which underwent acidification in the 1980s partially recovered. The O3 concentration at forest sites showed a decreasing trend. Consequently, AOT40 (the metric identified to protect vegetation from ozone pollution) showed a decrease, even if values were still above the limit for forest protection (5000 ppb h−1), while PODy (flux-based metric under discussion as new European legislative standard for forest protection) showed an increase. National scale studies pointed out that PM10 and NO2 induced about 58,000 premature deaths (year 2005), due to cardiovascular and respiratory diseases. The network identified for Italy contains a good number of monitoring sites (6 for terrestrial ecosystem monitoring, 4 for water bodies monitoring and 11 for ozone impact monitoring) distributed over the territory and will produce a high number of monitored parameters for the implementation of the NECD.

Mitotic Slippage Process Concealed Cancer-Sought Chromosome Instability Mechanism (S-CIN)

Official (NIH) cancer investigation is on identification of inherited cancer genes in you and me for early interventions, and for use of such knowledge in therapy. In this review the emphasis is on the unknown cancer initiation, and on the question of a mechanism for inherited CIN (chromosomal instability). Evidence for fitness increased cells from the mitotic slippage process (in vivo/in vitro) originated from genome damaged diploid cells in G2/M, skipping mitosis to G1, which illegitimately permitted S-phase re-replication of the chromatid cohesed-2n cells to 4n-tetraploidy. During which, down-load of genome-wide cohesin occurred, producing 4-chromatid diplochromosomes, evolutionary conserved in repair of DNA. This type of 4n cells divided 2-step meiotic-like, leading to diploid aneuploid cells with increased fitness, and expression of gross chromosomal anomalies in proliferation. The diploid cohesed chromatids during re-replication would hinder replication of sticky heterochromatic regions, resulting in their under-replication, and known from Drosophila. The human chromosomes are longitudinally differentiated into satellite DNA regions, folic acid sensitive sites and the primary constriction (centromere); they are breakage sensitive regions and being heterochromatic. This strongly suggests, multiple, chromosomal regional under-replication-cites, translated to origin of slippage, S-CIN, a genome inherited destabilization mechanism. Logically, S-CIN would affect genes differentially depending on chromosome location, for example, the high frequency in cancers of mutated p53 on the small 17p-arm, which with centromere breakage would be preferentially lost in mitosis. This likely S-CIN mechanism in cancer evolution can be studied in vivo for APC mutated crypt cells with demonstrated mitotic slippage process.

Trends in Surface Water Chemistry in Acidified Areas in Europe and North America from 1990 to 2008

Acidification of lakes and rivers is still an environmental concern despite reduced emissions of acidifying compounds. We analysed trends in surface water chemistry of 173 acid-sensitive sites from 12 regions in Europe and North America. In 11 of 12 regions, non-marine sulphate (SO4*) declined significantly between 1990 and 2008 (−15 to −59 %). In contrast, regional and temporal trends in nitrate were smaller and less uniform. In 11 of 12 regions, chemical recovery was demonstrated in the form of positive trends in pH and/or alkalinity and/or acid neutralising capacity (ANC). The positive trends in these indicators of chemical recovery were regionally and temporally less distinct than the decline in SO4* and tended to flatten after 1999. From an ecological perspective, the chemical quality of surface waters in acid-sensitive areas in these regions has clearly improved as a consequence of emission abatement strategies, paving the way for some biological recovery.

Contemporary Trends in the Acid–Base Status of Two Acid-Sensitive Streams in Western Maryland

Recovery of streamwater acid neutralizing capacity (ANC) resulting from declines in regional acid deposition was examined using contemporary (1990-2005) data from two long-term monitoring stations located on the Appalachian Plateau in western Maryland, U.S. Two computational methods were used to estimate daily, monthly, and annual fluxes and discharge-weighted concentrations of ANC, sulfate, nitrate, and base cations over the period of record, and two statistical methods were used to evaluate long-term trends in fluxes and concentrations. The methods used to estimate concentrations, as well as the statistical techniques, produced very similar results, underlining the robustness of the identified trends. We found clear evidence that streamwater sulfate concentrations have declined at an average rate of about 3 microeq L(-1) yr(-1) at the two sites due to a 34% reduction in wet atmospheric sulfur deposition. Trends in nitrate concentrations appear to be related to other watershed factors, especially forest disturbance. The best evidence of recovery is based on a doubling of ANC (from 21 to 42 microeq L(-1)) at the more acid-sensitive site over the 16-year period. A slowing, or possible reversal, in the sulfate, nitrate, and SBC trends is evident in our data and may portend a decline in the rate of--or end to--further recovery.

Water chemistry in forested acid sensitive sites in sub-tropical Asia receiving acid rain and alkaline dust

Acid rain, due to wet and dry deposition of S and N compounds, is an increasing environmental problem in China. A considerable deposition of alkaline dust serves to mitigate the acidifying effect to varying extent. Data from 3 years, a monitoring of water chemistry in 10 water compartments (i.e., two qualities of deposition, two types of throughfall, solution in five genetic soil horizons, and runoff) at five well documented sub-tropical forested catchments, have been interpreted in order to identify key processes governing the water chemistry in catchments suffering acid rain. This study of water chemistry in regions with sub-tropical climate supplements similar monitoring studies conducted in temperate regions with different types of soils and compositions of deposition. Natural organic acids as well as nutrient cycling of K + have strong influence on the water chemistry in throughfall and upper soil horizons at the relatively pristine sites. At sites receiving elevated S and N deposition an accelerated cycling of K + removes much of the mineral acidity in throughfall. The soil uptake of this K + results in release of H +. Nitrification and/or assimilation of a substantial deposition of reduced N contributes at some sites also significantly to the acidity in the soils. During the study period, Ca 2+ in solution was exchanged for Al 3+ in the soils with an effective base saturation less than 20%. In deeper soil horizons most of this mobilized Al is re-adsorbed along with SO 4 2 - .

Continuous cover forestry: possible implications for surface water acidification in the UK uplands

Abstract. The effects of widespread conifer afforestation on the acidity of lakes and streams in the acid sensitive uplands of the UK has been researched extensively and has contributed to the development and implementation of national forest management guidelines (e.g. Forest and Water Guidelines; Forestry Commission, 1993). However, a recent policy document (Woodlands for Wales; National Assembly for Wales, 2000) has proposed a major shift in the management of 50% of the Forestry Commission estate in Wales from the current system of patch clearfelling to Continuous Cover Forestry (CCF). This scale of change is without precedent in the UK; no studies in the UK forest environment have examined the likely environmental impacts of CCF. However, the wealth of environmental data from studies of UK forests managed by patch clearfelling enables an assessment of the impact of a change to CCF on three issues of particular relevance to surface water acidification in the uplands; forest harvesting, soil base cation depletion and atmospheric pollutant deposition. Whilst there is uncertainty as to how even-aged stands will be transformed to CCF in the UK, guiding principles for CCF on acidic and acid sensitive sites should focus on those aspects of management which minimise nitrate leaching, encourage base cation retention within the soil-plant system and enhance base cation inputs from external (atmospheric) and internal sources (weathering). CCF may provide opportunities to achieve this by reducing the scale of clearfelling, increasing species diversity, changing the structure of plantation forests and maintaining uninterrupted woodland cover. Keywords: acidification, forestry, continuous cover forestry, clearfelling

An Assessment of the potential impact of the Gothenburg Protocol on surface water chemistry using the dynamic MAGIC model at acid sensitive sites in the UK

Abstract. The MAGIC model has been systematically calibrated to 12 sites in the UK, which form part of the UK Acid Waters Monitoring Network, using best available data. The model successfully simulates observed changes in major ions and acid neutralising capacity over the period 1988 to 2000. Predictions for the future are made assuming no further emission reductions from present day (constant deposition at current level) compared to reduced sulphur and nitrogen emission agreed under the Gothenburg Protocol (reduced sulphur dioxide emission by c.80%, nitrogen oxides by c.45% and ammonia by 20% by 2010). In addition, uncertainty in our understanding of future nitrogen dynamics is assessed using "best" and "worst" cases of nitrogen leaching in the model. The results clearly indicate the need to achieve further emission reductions in sulphur and nitrogen beyond present day levels to prevent continued surface water acidification. The predictions further indicate that if the emission reductions agreed under the Gothenburg Protocol are achieved by 2010 this will promote a recovery in acid neutralising capacity by 2020 at all sites. Differences between "best" and "worst" case nitrate leaching are relatively small, emphasising the need to achieve the sulphur reductions in the shorter term. In the longer term, beyond 2020, increased nitrogen leaching under the "worst case" leading to further acidification is likely indicating a need for further reduction of nitrogen emissions. Keywords: acidification, recovery, model, Gothenburg Protocol, nitrogen

Aluminium Mobility at an Acid Sensitive Site with High S-Deposition

Soil water at an acid-sensitive forested catchment in southwestern Poland has been studied for four years. Median base saturation (BS) is only 5% in the podzol B-horizons. Very low pH values in the soil water from the O-horizons (10- and 90 percentiles pH 3.5 and 4.3) increased to a typical median pH in the B-horizons of 4.4, mainly by release of inorganic labile aluminium (Ali). Median concentrations in the B horizons were 3.4mg Ali L−1. Al-soil/soilwater interactions were studied over a large span of sulphate concentrations resulting from both a generally decreasing S-deposition during the last decades and an increase in precipitation during the study period. These changes led sulphate to leach from the mineral soil.

Will reduced sulphur emissions under the Second Sulphur Protocol lead to recovery of acid sensitive sites in UK?

A conceptual model of the combined effects of acid deposition and land-use, Model of Acidification of Groundwater In Catchments (MAGIC), was applied to 21 upland sites in the UK Acid Waters Monitoring Network (AWMN) to assess the likely future recovery in response to the latest international agreements controlling anthropogenic sulphur emissions throughout Europe. Future estimates of sulphur deposition were generated by the Hull Acid Rain Model (HARM), based on the agreed reductions outlined in the Second Sulphur Protocol. The results indicate only a limited degree of recovery in surface-water chemistry at all sites over the next 50 years; moreover, a continuing decline in soil base status is predicted to occur at 70% of sites, resulting in longer term reacidification of surface-water at 38% of sites. However, compared with a ‘business as usual’ scenario the recovery is pronounced, although acidified sites will require further reductions in acidic deposition if recovery to pre-industrial chemical conditions are to be achieved. Furthermore, land-use scenarios at afforested sites suggest that replanting of felled forest will lead to a further increase in acidification. This strengthens the argument that plantation forestry should be avoided in areas considered geologically sensitive to acidic deposition.

Experimental acidification of alpine catchments at Sogndal, Norway: Results after 8 years

Manipulations with whole catchments were initiated in Norway in 1983 (RAIN project Reversing Acidification In Norway) to obtain direct experimental evidence relating to the reversibility of soil and water acidification, rate of change, and the relative roles of sulfur and nitrogen. We present here results for soil and runoff chemistry during 8 years of acid addition at Sogndal, a pristine acid-sensitive site in central Norway characterized by gneissic bedrock, thin and patchy soils, and alpine vegetation. Catchment SOG2 receives 100 meq m−2 yr−1 H2SO4, catchment SOG4 receives a 1∶1 mixture of H2SO4 and HNO3, while catchments SOG1 and SOG3 serve as untreated controls. Acid is applied to the snowpack in April and in 5 portions of 11 mm of pH 3.2 acidified lakewater during the snowfree period.