in france, germany, and italy. in switzerland, where neonicotinoids were never used in alpine areas, neonics were banned because of accidental poisonings of bee populations and the relatively low safety margin for other beneficial insects. environmentalists called the move "a significant victory for common sense and our beleaguered bee populations" and said it is "crystal clear that there is overwhelming scientific, political and public support for a ban." the uk, which voted against the bill, disagreed: "having a healthy bee population is a top priority for us, but we did not support the proposal for a ban because our scientific evidence doesn't support it." bayer cropscience, which makes two of the three banned products, remarked "bayer remains convinced neonicotinoids are safe for bees, when used responsibly and properly … clear scientific evidence has taken a back-seat in the decision-making process." reaction in the scientific community was mixed. biochemist lin field said the decision was based on "political lobbying" and could lead to the overlooking of other factors involved in colony collapse disorder. zoologist lynn dicks of cambridge university disagreed, saying "this is a victory for the precautionary principle, which is supposed to underlie environmental regulation." simon potts, professor of biodiversity and ecosystem services at reading university, called the ban "excellent news for pollinators", and said, "the weight of evidence from researchers clearly points to the need to have a phased ban of neonicotinoids." the decision came up for review in 2016. in march 2017, the guardian printed an article which claimed that they had obtained information that indicated that the european commission wanted a complete ban and cited "high acute risks to bees". a vote on the ban was expected in 2017 but delayed until early 2018 to assess the scientific findings. on 27 april 2018, member states of the european union agreed upon a total ban on neonicotinoid insecticide use, except within closed greenhouses, to be imposed from the end of 2018. the ban applies to the three main neonicotinoid active compounds: clothianidin, imidacloprid and thiamethoxam. use of the three compounds had been partially restricted in 2013. the vote on the proposed ban followed a february 2018 report from the european food safety authority which concluded that neonicotinoids posed a high risk to both domestic and wild bees. voting on the issue had previously been postponed on multiple occasions. the ban had strong public support, but faced criticism from the agrochemical industry, and from certain farmers' groups. the ban on neonicotinoids caused jaundice devastation in certain sugar beet fields, reducing harvests in one of the world's largest beet sugar producers and endangering the industry. france subsequently extended the ban until 2023. economic impact in january 2013, the humboldt forum for food and agriculture e. v. (hffa), a non-profit think tank, published a report on the value of neonicotinoids in the eu. at their website hffa lists as their partners/supporters: basf se, the world's largest chemical company; bayer cropscience, makers of products for crop protection and nonagricultural pest control; e.on, an electric utility service provider; kws seed, a seed producer; and the food company nestlé. the study was supported by copa-cogeca, the european seed association and the european crop protection association, and financed by neonicotinoid manufacturers bayer cropscience and syngenta. the report looked at the short- and medium-term impacts of a complete ban of all neonicotinoids on agricultural and total value added (va) and employment, global prices, land use and greenhouse gas (ghg) emissions. in the first year, agricultural and total va would decline by €2.8 and €3.8 billion, respectively. the greatest losses would be in wheat, maize and rapeseed in the uk, germany, romania and france. 22,000 jobs would be lost, primarily in romania and poland, and agricultural incomes would decrease by 4.7%. in the medium-term (5-year ban), losses would amount to €17 billion in va, and 27,000 jobs. the greatest income losses would affect the uk, while most jobs losses would occur in romania. following a ban, the lowered production would induce more imports of agricultural commodities into the eu. agricultural production outside the eu would expand by 3.3 million hectares, leading to additional emissions of 600 million tons of carbon dioxide equivalent. when the report was released, peter melchett, policy director of the soil association, which has been working to ban neonicotinoids in the uk, commented that since the report was funded by bayer crop sciences and syngenta, "it was probably unlikely to conclude that neonicotinoids should be banned". the spokesperson further stated: "on the one hand, the chemical companies say we risk the additional costs to farmers amounting to £630 million. on the other, the possible cost of losing pollinating insects is thought to be worth three times as much (£1.8 billion*) to uk farmers." canada use of pesticides in canada is a matter of federal jurisdiction. in 2016, health canada proposed phasing out imidacloprid over the next three to five years. the government has voiced concerns regarding the impact of neonics on bees, invertebrate waterspecies, and birds. in ontario, nearly all corn seeds and a majority of soybeans get treated with neonicotinoids. in the summer of 2015, the province passed a law to reduce the presence of neonicotinoids. ontario's regulations were written to reduce the percent of seeds and beans covered with neonicotinoids to 20 percent within two years. on 10 december 2015, montreal banned all neonicotinoids – without exception – on all properties within the city limits, including the botanical garden, all agricultural areas and all golf courses. agricultural businesses opposed montreal's ban. in july 2016, british columbia's largest city, vancouver, banned the use of neonics within vancouver city limits, where it was primarily being used to kill off chafer beetles living under home lawns. oceania on 11 october 2019, the fiji government announced a ban on imidacloprid, effective 1 january 2020. chemical activity and properties neonicotinoids, like nicotine, bind to nicotinic acetylcholine receptors (nachrs) of a cell and trigger a response by that cell. in mammals, nicotinic acetylcholine receptors are located in cells of both the central nervous system and peripheral nervous systems. in insects these receptors are limited to the central nervous system. nicotinic acetylcholine receptors are activated by the neurotransmitter acetylcholine. while low to moderate activation of these receptors causes nervous stimulation, high levels overstimulate and block the receptors, causing paralysis and death. acetylcholinesterase breaks down acetylcholine to terminate signals from these receptors. however, acetylcholinesterase cannot break down neonicotinoids and their binding is irreversible. basis of selectivity r-nicotine (top) and desnitro-imidacloprid are both protonated in the body mammals and insects have different composition of the receptor subunits and the structures of the receptors. because most neonicotinoids bind much more strongly to insect neuron receptors than to mammal neuron receptors, these insecticides are more toxic to insects than mammals. the low mammalian toxicity of imidacloprid has been explained by its inability to cross the blood–brain barrier because of the presence of a charged nitrogen atom at physiological ph. the uncharged molecule can penetrate the insect blood–brain barrier. other neonicotinoids have a negatively charged nitro or cyano group, which interacts with a unique, positively charged amino acid residue present on insect, but not mammalian nachrs. however, the breakdown product desnitro-imidacloprid, which is formed in a mammal's body during metabolism as well as in environmental breakdown of imidacloprid, has a charged nitrogen and shows high affinity to mammalian nachrs. desnitro-imidacloprid is quite toxic to mice. toxic action may result from the active ingredient itself or from its residue. 6-chloronicotinic acid is a common degradation product of multiple neonicotinoids. persistence and half-life most neonicotinoids are water-soluble and break down slowly in the environment, so they can be taken up by the plant and provide protection from insects as the plant grows. independent studies show that the photodegradation half-life time of most neonicotinoids is around 34 days when exposed to sunlight. however, it might take up to 1,386 days (3.8 years) for these compounds to degrade in the absence of sunlight and micro-organism activity. some researchers are concerned that neonicotinoids applied agriculturally might accumulate in aquifers. environmental and species impact bees