Effects of UV radiation on natural and synthetic materials.

The deleterious effects of solar ultraviolet (UV) radiation on construction materials, especially wood and plastics, and the consequent impacts on their useful lifetimes, are well documented in scientific literature. Any future increase in solar UV radiation and ambient temperature due to climate change will therefore shorten service lifetimes of materials, which will require higher levels of stabilisation or other interventions to maintain their lifetimes at the present levels. The implementation of the Montreal Protocol and its amendments on substances that deplete the ozone layer, controls the solar UV-B radiation received on Earth. This current quadrennial assessment provides a comprehensive update on the deleterious effects of solar UV radiation on the durability of natural and synthetic materials, as well as recent innovations in better stabilising of materials against solar UV radiation-induced damage. Pertinent emerging technologies for wood and plastics used in construction, composite materials used in construction, textile fibres, comfort fabric, and photovoltaic materials, are addressed in detail. Also addressed are the trends in technology designed to increase sustainability via replacing toxic, unsustainable, legacy additives with 'greener' benign substitutes that may indirectly affect the UV stability of the redesigned materials. An emerging class of efficient photostabilisers are the nanoscale particles that include oxide fillers and nanocarbons used in high-performance composites, which provide good UV stability to materials. They also allow the design of UV-shielding fabric materials with impressive UV protection factors. An emerging environmental issue related to the photodegradation of plastics is the generation of ubiquitous micro-scale particles from plastic litter exposed to solar UV radiation.

Environmental effects of stratospheric ozone depletion, UV radiation, and interactions with climate change: UNEP Environmental Effects Assessment Panel, Update 2021.

The Environmental Effects Assessment Panel of the Montreal Protocol under the United Nations Environment Programme evaluates effects on the environment and human health that arise from changes in the stratospheric ozone layer and concomitant variations in ultraviolet (UV) radiation at the Earth's surface. The current update is based on scientific advances that have accumulated since our last assessment (Photochem and Photobiol Sci 20(1):1-67, 2021). We also discuss how climate change affects stratospheric ozone depletion and ultraviolet radiation, and how stratospheric ozone depletion affects climate change. The resulting interlinking effects of stratospheric ozone depletion, UV radiation, and climate change are assessed in terms of air quality, carbon sinks, ecosystems, human health, and natural and synthetic materials. We further highlight potential impacts on the biosphere from extreme climate events that are occurring with increasing frequency as a consequence of climate change. These and other interactive effects are examined with respect to the benefits that the Montreal Protocol and its Amendments are providing to life on Earth by controlling the production of various substances that contribute to both stratospheric ozone depletion and climate change.

Environmental effects of stratospheric ozone depletion, UV radiation, and interactions with climate change: UNEP Environmental Effects Assessment Panel, Update 2020.

This assessment by the Environmental Effects Assessment Panel (EEAP) of the United Nations Environment Programme (UNEP) provides the latest scientific update since our most recent comprehensive assessment (Photochemical and Photobiological Sciences, 2019, 18, 595-828). The interactive effects between the stratospheric ozone layer, solar ultraviolet (UV) radiation, and climate change are presented within the framework of the Montreal Protocol and the United Nations Sustainable Development Goals. We address how these global environmental changes affect the atmosphere and air quality; human health; terrestrial and aquatic ecosystems; biogeochemical cycles; and materials used in outdoor construction, solar energy technologies, and fabrics. In many cases, there is a growing influence from changes in seasonality and extreme events due to climate change. Additionally, we assess the transmission and environmental effects of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is responsible for the COVID-19 pandemic, in the context of linkages with solar UV radiation and the Montreal Protocol.

Environmental effects of stratospheric ozone depletion, UV radiation and interactions with climate change: UNEP Environmental Effects Assessment Panel, update 2019.

This assessment, by the United Nations Environment Programme (UNEP) Environmental Effects Assessment Panel (EEAP), one of three Panels informing the Parties to the Montreal Protocol, provides an update, since our previous extensive assessment (Photochem. Photobiol. Sci., 2019, 18, 595-828), of recent findings of current and projected interactive environmental effects of ultraviolet (UV) radiation, stratospheric ozone, and climate change. These effects include those on human health, air quality, terrestrial and aquatic ecosystems, biogeochemical cycles, and materials used in construction and other services. The present update evaluates further evidence of the consequences of human activity on climate change that are altering the exposure of organisms and ecosystems to UV radiation. This in turn reveals the interactive effects of many climate change factors with UV radiation that have implications for the atmosphere, feedbacks, contaminant fate and transport, organismal responses, and many outdoor materials including plastics, wood, and fabrics. The universal ratification of the Montreal Protocol, signed by 197 countries, has led to the regulation and phase-out of chemicals that deplete the stratospheric ozone layer. Although this treaty has had unprecedented success in protecting the ozone layer, and hence all life on Earth from damaging UV radiation, it is also making a substantial contribution to reducing climate warming because many of the chemicals under this treaty are greenhouse gases.

Interactive effects of solar UV radiation and climate change on material damage.

Solar UV radiation adversely affects the properties of organic materials used in construction, such as plastics and wood. The outdoor service lifetimes of these materials are influenced by their rates of degradation under solar UV radiation as well as by other climate factors such as temperature, moisture, and atmospheric pollutants. While recovery of the stratospheric ozone layer is expected, local increases in UV radiation are still likely to occur, especially in the tropics, but also elsewhere because of climate change effects. Such increases, when taken together with an increased ambient temperature due to climate change, can significantly shorten the service lifetimes of organic building materials. Several proven technologies, including the use of UV stabilisers, surface treatments or coatings have been developed over the years to mitigate these adverse effects. While these technologies should be able to compensate for any realistic future UV radiation and climate change scenarios, they will also add significantly to the lifetime cost of material in relevant products. Shorter outdoor lifetime of the plastic components in photovoltaic (PV) modules is a serious concern in the solar energy industry. To ensure module durability over the full service-lifetime (of about ∼20 years) of the light-harvesting PV components, better stabilisation technologies are being investigated. The present trend towards more environmentally sustainable materials in building, and environmental impact of additives such as stabilisers, need to be considered in addition to their engineering performance. This may require the phasing out of some conventional additives used in plastics as well as substituting wood or other materials in place of plastics in buildings. Depending on the relative costs of mitigation, substituting more UV-stable materials for conventional ones in outdoor products may also be a viable option with some categories of products. Neither the global cost of mitigation of the effects of climate change on materials nor the long-term sustainability of the technologies available for the purpose, have been estimated. Plastic waste and litter exposed outdoors to solar UV radiation over extended periods undergo cracking and fragmentation into small pieces (of micro- and nano-scale size). Release of these fragments into the environment, particularly in the aquatic environment, poses a potential threat to marine biota. Already several hundred of species are known to ingest these fragments that can potentially accumulate additives and pollutants from water. This is a potential threat to humans because 25% of fish marketed for human consumption have been reported to contain microplastics in their digestive systems. The focus of this assessment is on recent advances in understanding the mechanisms of UV-radiation-induced degradation in materials and in assessing emerging technologies for their stabilisation against outdoor UV-degradation. A better understanding of the mechanisms of degradation will allow for innovative stabilisation approaches to be developed. Also assessed is information on the sustainability of the available and emerging UV stabilisation technologies.

Pathogen-specific production losses in bovine mastitis.

Reduction in long-term milk yields represents a notable share of the economic losses caused by bovine mastitis. Efficient, economic, and safe measures to prevent these losses require knowledge of the causal agent of the disease. The aim of this study was to investigate pathogen-specific impacts of mastitis on milk production of dairy cows. The materials consisted of milk and health recording data and microbiological diagnoses of mastitic quarter milk samples of 20,234 Finnish dairy cows during 2010, 2011, and 2012. The 6 most common udder pathogens were included in the study: Staphylococcus aureus, non-aureus staphylococci (NAS), Escherichia coli, Corynebacterium bovis, Streptococcus uberis, and Streptococcus dysgalactiae. We used a 2-level multilevel model to estimate curves for lactations with and without mastitis. The data on lactation periods to be compared were collected from the same cow. To enable comparison among lactations representing diverse parities, the estimated lactation curves were adjusted to describe the cow's third lactation. Mastitis caused by each pathogen resulted in milk production loss. The extent of the reduction depended on the pathogen, the timing of mastitis during lactation, and the type of mastitis (clinical vs. subclinical). The 2 most commonly detected pathogens were NAS and Staph. aureus. Escherichia coli clinical mastitis diagnosed before peak lactation caused the largest loss, 10.6% of the 305-d milk yield (3.5 kg/d). The corresponding loss for Staph. aureus mastitis was 7.1% (2.3 kg/d). In Staph. aureus mastitis diagnosed between 54 and 120 d in milk, the loss was 4.3% (1.4 kg/d). The loss was almost equal in both clinical and subclinical mastitis caused by Staph. aureus. Mastitis caused by Strep. uberis and Strep. dysgalactiae resulted in losses ranging from 3.7% (1.2 kg/d) to 6.6% (2.1 kg/d) depending on type and timing of mastitis. Clinical mastitis caused by the minor pathogens C. bovis and NAS also had a negative effect on milk production: 7.4% (2.4 kg/d) in C. bovis and 5.7% (1.8 kg/d) in NAS when both were diagnosed before peak lactation. In conclusion, minor pathogens should not be underestimated as a cause of milk yield reduction. On single dairy farms, control of E. coli mastitis would bring about a significant increase in milk production. Reducing Staph. aureus mastitis is the greatest challenge for the Finnish dairy sector.

Environmental effects of ozone depletion, UV radiation and interactions with climate change: UNEP Environmental Effects Assessment Panel, update 2017.

The Environmental Effects Assessment Panel (EEAP) is one of three Panels of experts that inform the Parties to the Montreal Protocol. The EEAP focuses on the effects of UV radiation on human health, terrestrial and aquatic ecosystems, air quality, and materials, as well as on the interactive effects of UV radiation and global climate change. When considering the effects of climate change, it has become clear that processes resulting in changes in stratospheric ozone are more complex than previously held. Because of the Montreal Protocol, there are now indications of the beginnings of a recovery of stratospheric ozone, although the time required to reach levels like those before the 1960s is still uncertain, particularly as the effects of stratospheric ozone on climate change and vice versa, are not yet fully understood. Some regions will likely receive enhanced levels of UV radiation, while other areas will likely experience a reduction in UV radiation as ozone- and climate-driven changes affect the amounts of UV radiation reaching the Earth's surface. Like the other Panels, the EEAP produces detailed Quadrennial Reports every four years; the most recent was published as a series of seven papers in 2015 (Photochem. Photobiol. Sci., 2015, 14, 1-184). In the years in between, the EEAP produces less detailed and shorter Update Reports of recent and relevant scientific findings. The most recent of these was for 2016 (Photochem. Photobiol. Sci., 2017, 16, 107-145). The present 2017 Update Report assesses some of the highlights and new insights about the interactive nature of the direct and indirect effects of UV radiation, atmospheric processes, and climate change. A full 2018 Quadrennial Assessment, will be made available in 2018/2019.

Factors associated with intramammary infection in dairy cows caused by coagulase-negative staphylococci, Staphylococcus aureus, Streptococcus uberis, Streptococcus dysgalactiae, Corynebacterium bovis, or Escherichia coli.

The aim of this study was to determine risk factors for bovine intramammary infection (IMI) associated with the most common bacterial species in Finland. Large databases of the Finnish milk-recording system and results of microbiological analyses of mastitic milk samples from Valio Ltd. (Helsinki, Finland) were analyzed. The study group comprised 29,969 cows with IMI from 4,173 dairy herds. A cow with a quarter milk sample in which DNA of target species was detected in the PathoProof Mastitis PCR Assay (Thermo Fisher Scientific, Waltham, MA) was determined to have IMI. Only cows with IMI caused by the 6 most common pathogens or groups of pathogens, coagulase-negative staphylococci (CNS), Staphylococcus aureus, Streptococcus uberis, Streptococcus dysgalactiae, Corynebacterium bovis, and Escherichia coli, were included. The control group comprised 160,176 IMI-free cows from the same herds as the study group. A multilevel logistic regression model was used to study herd- and cow-specific risk factors for incidence of IMI. Pathogen-specific results confirmed those of earlier studies, specifically that increasing parity increases prevalence of IMI regardless of causative pathogen. Holsteins were more susceptible to IMI than Nordic Reds except when the causative pathogen was CNS. Occurrence of IMI caused by C. bovis was not related to milk yield, in contrast to IMI caused by all other pathogens investigated. Organic milk production was associated with IMI only when the causative pathogen of IMI was Staph. aureus; Staph. aureus IMI was more likely to occur in conventional than in organic production. Cows in older freestall barns with parlor milking had an increased probability of contracting an IMI compared with cows in tiestall barns or in new freestall barns with automatic milking. This was the case for all IMI, except those caused by CNS, the prevalence of which was not associated with the milking system, and IMI caused by Staph. aureus, which was most common in cows housed in tiestall barns. A better breeding index for milk somatic cell count was associated with decreased occurrence of IMI, indicating that breeding for improved udder health has been successful in reducing the incidence of IMI caused by the most common pathogens in Finland. In the Finnish dairy sector, the importance of other measures to control IMI will increase as the Holstein breed progressively takes the place of the Nordic Red breed. Attention should be paid to hygiene and cleanliness, especially in old freestall barns. Based on our results, the increasing prevalence of automatic milking is not a reason for special concern.

Optimal utilization of modern reproductive technologies to maximize the gross margin of milk production.

In this study, a linear programming model was developed to maximize the gross margin of milk production by determining the optimal use of different reproductive technologies in a dairy herd. The model has the potential to vary the use of conventional artificial insemination, insemination with X-sorted sperm, and the use of unselected or sex-selected embryo recovery and transfer. Data from Finnish dairy herd recording systems were used to parameterize the model. This paper presents the results of 6 scenarios for a herd size of 60 dairy cows. In the basic scenario, the optimum economic combination for Finnish conditions was to inseminate 10 heifers and 22 cows with unsorted semen, 8 heifers with X-sorted sperm, and to use 20 cows as embryo donors which was the upper constraint for this technique. The embryo donors were inseminated with conventional semen for both embryo production and their subsequent pregnancy. Without restriction on embryo recovery, the optimum combination was to use all heifers as donors of sex-selected embryos and all cows as donors of unselected embryos. It was more profitable to produce female embryos with X-sorted sperm than by sorting embryos. Embryo recipients were not economically justified in any scenario. In practice, the optimal strategy is herd-specific depending on the input costs, output values and the technical success of each reproductive technology in that herd. This single-year linear programming model adequately differentiates between breeding technologies within a herd, but further research is needed to develop dynamic models to consider genetic improvement and herd expansion.

Costs of clinical mastitis with special reference to premature culling.

Bovine mastitis is an economic and a welfare problem on dairy farms. The objective of this study was to estimate the costs of clinical mastitis (CM), having a special focus on the cost variation related to culling decisions. A dynamic optimization model was developed to determine an optimal replacement time of a mastitic cow and to estimate the costs of CM, taking into account the risk of premature culling and the uncertainty in CM prevalence. Six lactations were analyzed at monthly periods for Ayrshire and Holstein-Friesian breeds. The estimates reflect Finnish production conditions where mastitis is treated only by veterinarians. Biological parameters of the model were adapted from the literature and the Finnish dairy herd health recording system. Field data were used to produce the risk parameters of culling due to mastitis on commercial dairy farms. The model recommended treating the cows with CM and keeping them in most cases until their fifth lactation. A cheaper (-20%) heifer transferred the optimum to the previous lactation and a more expensive (+20%) heifer to the following lactation. Conditional on optimal replacements, the average cost of CM of an Ayrshire (Holstein-Friesian costs in parentheses) cow was €485 (€458), varying from €209 (€112) to €1,006 (€946). The costs were at the highest when the occurrence of CM was at a top yield phase. In the scenario where the risk of culling due to mastitis was included in the model, the average cost of CM was €596 (€623). Disposing of a young cow at the end of her first lactation month caused the highest costs. The costs converted to figures per cow-year were €121 (€147) with optimal cullings and €155 (€191) in the current Finnish conditions. Thus, the increase in the costs of CM due to premature cullings was 28% (30%.) The main cost sources were long-term production losses regardless of the culling decisions. Premature culling formed 20% (23%) of the total costs. To decrease the costs of CM, more emphasis should be given to hidden costs, especially the high cost of premature culling should be underlined.

Optimal replacement policy and economic value of dairy cows with diverse health status and production capacity.

Understanding optimal replacement practices is essential in milk production management. In this study, we produced a stochastic dynamic optimization model that included the risk of diseases. Moreover, the study took into consideration the genetic production capacity of a cow and the uncertainty related to it. We determined the optimal replacement policy separately for Ayrshire and for Holstein-Friesian Finnish herds. The need for veterinary treatments and the probability of involuntary culling were estimated from the Finnish dairy herd health recording system. We found that the portion of involuntary culling was approximately 50% of present disposals. The need for veterinary treatments and the probability of involuntary culling were higher for Holstein-Friesian than for Ayrshire cows. Regardless of health status, only the oldest cows with low production capacity should be disposed of intentionally. In the postoptimization steady state, the mean parity was 3.8 and 3.7 for Ayrshire and Holstein-Friesian herds, respectively. Under current management practice, the mean is only 2.3 parities. Preventing premature culling of dairy cows is important to improve the possibilities of breeding selection and the economic performance of milk production. The expected net present value of a cow was slightly higher in Ayrshire than in Holstein-Friesian herds. The results indicate that in the long run, it is worth paying attention to the health status and longevity of a cow as well as to its high yield.

Use of medication during pregnancy--a prospective cohort study on use and policy of prescribing.

Pregnancy is associated with special problems with respect in selection of medication and dosage, primarily due to potential teratogenic or toxic effects on the fetus by the drug itself, and secondly due to the physiologic adjustments in the mother in response to pregnancy. This prospective survey was designed to record the use of medications and the policy of prescribing during the course of pregnancy. In total, 5851 pregnant women residing in a county in southwestern Finland during the period June 15, 1987 and June 14, 1988 were studied, which is 69% of the total amount of births in the same area. Iron and vitamin supplementation was used by all the pregnant women during the third trimester, and by 35% and 88% during the first and second trimesters, respectively. Analgetics were used on an irregular basis by 12% of the pregnant women, and no correlation to the length of pregnancy could be observed. 9% of the women used medication on a regular basis for reasons such as bronchial asthma, arterial hypertension and hyperthyreosis. Some kind of a symptomatic medication was taken by 43% of the women with no correlation of the length of pregnancy, the most common symptoms needing medication being candidiasis, cough, reflux esophagitis and pregnancy-associated hyperemesis. Tocolytic agents had been given to 8% of the pregnant women. Most tocolytics were used during the end of the second trimester and beginning of the third one. It is concluded that the general use of medicines is quite reasonable in the normal pregnant population in Finland. Iron supplementation should probably be more individualized instead of regular use.

Antibiotics in pregnancy--a prospective cohort study on the policy of antibiotic prescription.

Pregnancy is associated with special problems with respect to antibiotic selection and dosage due to potential teratogenic or toxic effects on the fetus by the drug itself, and the great physiological adjustments in the mother. This survey was designed to record the use of antibiotics and the policy of prescription of antimicrobial drugs during the course of pregnancy. In total, 4055 pregnant women residing in a county in south-western Finland during the period June 15, 1987-June 14, 1988 were studied. Penicillin, erythromycin and pivmecillinam were the most often used antibiotics during pregnancy comprising together 65.4% of all antibiotic use; 94.1% of all antimicrobial medication was administered orally. The highest incidence for antibiotic use (45.4% of all) as well as for treated infections (45% of all) was at the second trimester. The duration of medication was commonly 10 days (44.4%, SD 14.6) or 7 days (27.9%, SD 7.7). Penicillin was in a few cases prescribed at increased dosage (25.6%), while erythromycin and amoxicillin were occasionally administered at reduced dosages (30.2% and 42.5%, respectively). The dosages should probably be individualized more often, according to the information available on the pharmacokinetics of specific antibiotics during pregnancy. It may also be possible to reduce the length of antibiotic treatment for UTI.

The need for adjustment of dosage regimen of penicillin V during pregnancy.

OBJECTIVE: To determine whether the normal regimen of dosage of oral penicillin V is relevant during pregnancy. METHODS: Twelve pregnant and six nonpregnant women volunteered for the study. Six women were in the second trimester of pregnancy (mean +/- standard deviation 19 +/- 7 weeks' gestation) and six women were in the third trimester (35 +/- 2 weeks). All of the women took 1 x 10(6) IU phenoxymethylpenicillin orally, and multiple blood and urine samples were obtained. Assays were performed by means of a disk agar diffusion method. The results were compared by Mann-Whitney U test. RESULTS: Compared with nonpregnant women, pregnant women had smaller area under the curve values (433 +/- 93 minutes.IU/mL, P < .05 in the second trimester; 550 +/- 220 minutes.IU/mL in the third trimester) and a shorter half-life (57 +/- 56 minutes in the second trimester; 34 +/- 21 minutes, P < .05 in the third trimester). Plasma and renal clearances were faster in the pregnant women. CONCLUSION: Elimination of penicillin V is enhanced during pregnancy, necessitating either a shorter dosing interval (6-8 hours) or an increased dose with the standard dosing interval.