If Your City Sprays Pesticides on Its Green Spaces, How Much Do You Know About the Risks?

With no real standards and no real oversight, the pesticides used in urban greening are putting the environment and public health at risk. A few people are trying to change that.

On the evening of July 4, a government notice in Dalian's Peninsula Morning Post stopped Sun Kang cold. Sun is a professor at the Research Center for Marine Economy and Sustainable Development at Liaoning Normal University.

The notice said that to control forest pests and disease, the city's urban construction bureau would spray pesticide from the air on the 7th through the 15th of both July and August, over the districts of Zhongshan, Xigang and Shahekou, plus the Dalian Landscape and Gardening Administration, the Dalian Forest Zoo and Dalian Laohutan Ocean Park. The chemical was an insecticide called thiacloprid. Residents were told to keep doors and windows shut, not to hang laundry outdoors, and to spend less time outdoors among the trees. Aerial spraying, the notice said, "does no harm to people, livestock or poultry," though it admitted "some effect on insects such as silkworms and bees," and so required "units and individuals engaged in animal husbandry within the spray zone to take appropriate protective measures."

Sun Kang had never heard of the chemical. She looked it up and found it was a "neonicotinoid," a class of pesticide that threatens insects and birds alike — the European Union has already banned three of them from outdoor use.

The next afternoon, Sun went to the urban construction bureau with a reporter and a wildlife-protection volunteer to ask about it. Staff told her Dalian had an outbreak of pine wood nematode disease in 2016 and had sprayed from the air twice in 2017, using the same thiacloprid; the outbreak was still there this year, so the spraying would continue. Sun told QDaily that Zhongshan, Xigang and Shahekou are Dalian's densely populated core districts, and that before issuing the notice the government had neither carried out an environmental assessment of the spraying nor asked the public what it thought.

The meeting did not stop the plan. On the morning of July 7, Sun Kang stood in her home in Shahekou district and watched, uneasy, as a light helicopter passed overhead.

Chemical Greening and Where It Comes From

In China, pesticides in farming get close attention; pesticides in urban green spaces get very little. Aerial spraying may be rare, but research suggests the "routine" use is not much more reassuring.

In 2013, Lu Xiaoxia, an associate professor at Peking University's College of Urban and Environmental Sciences, went to Harvard as a visiting scholar to study neonicotinoid pesticides. A year later she returned to Beijing and began measuring how much of this class of pesticide lingers in the urban environments of Beijing and Tianjin. In February this year, the Tianjin half of the work was the first to appear, as a research paper in the international journal Analytica Chimica Acta. In soil from 35 parks and 33 residential areas in Tianjin, neonicotinoid residues were no lower than the known levels in farmland. In parks they were higher still, reaching the levels found in greenhouses, where pesticides are used constantly.

This may be the first study of neonicotinoid residues in China's urban environments, and one of only a handful of studies that put a number on urban pesticide residues of any kind in the country.

Lu Xiaoxia told QDaily that the Beijing results are not yet published, but the data look much like Tianjin's. So far, she added, the work in both cities only measures residue; it has not assessed the effects on the environment or on health. But existing research shows that neonicotinoids harm a wide range of invertebrates, bees included — above all by causing "colony collapse disorder," which has driven bee numbers sharply down across North America and Europe, far enough that people worry about the natural pollination of plants. They reach vertebrates too: birds can be poisoned by eating insects the chemical has killed, or seeds coated with it. Neonicotinoids excite the nicotinic acetylcholine receptors of neurons in the brains of rats, and so may harm human health as well, with the developing brain most at risk.

Cities are crowded, and people brush up against the plants in green spaces all the time — sitting down on the grass, for one — with no idea where pesticide has been sprayed, what was sprayed or how much, and usually no thought of being careful.

"Pesticides in public green spaces really are a problem," said the head of the planting office at the Shanghai Municipal Agricultural Commission, a man surnamed Li, by phone. But this is not the agriculture department's job, he said: "The Agricultural Commission only handles agricultural production and sales. Greening work belongs to the landscaping and city-appearance department, which has a duty to carry out the Regulations on Pesticide Administration in its own work." The new Regulations on Pesticide Administration, issued last year, state that alongside the agricultural authorities, "other relevant departments of people's governments at or above the county level shall be responsible for pesticide oversight within their respective areas of authority."

The Shanghai Greening Management Guidance Station sits under the city's Landscaping and City Appearance Administration Bureau; it gives technical guidance on pest control in green spaces and writes the industry's technical standards. A staff member who asked not to be named told QDaily that Shanghai's greening authorities have in fact been talking about "pollution-free maintenance" of public green spaces for 20 years, and that his own agency has long urged the whole industry toward "ecological maintenance" and "green pest control" — swapping ecological agents for chemical ones, for instance, and powders and water-based formulations for emulsifiable concentrates, which penetrate more deeply. When the government puts greening-maintenance work out to tender, it also asks bidders to follow ecological-maintenance principles, and discourages chemicals such as chlorpyrifos and phoxim.

But none of that is binding, he admitted. The agricultural authorities have a dedicated enforcement arm to police pesticide use. The landscaping and city-appearance department has none. So in practice maintenance contractors still use organophosphates such as chlorpyrifos, which is more toxic than the neonicotinoids. Chlorpyrifos, he added, is cheap and works on the spot: spray a tree and the insects rain down, saving time and labor. It is especially handy when a surprise inspection from above has to be dealt with.

As he sees it, maintenance crews lean on chemical pesticides largely to hold costs down. In recent years Shanghai has run greening maintenance on a "territorial management" system that pushes responsibility down to district and sub-district governments, and the tender budgets that come out of it are very low. For the contractors, cheap and effective chemicals are the obvious place to save. Ecological pesticides cost several times more, work less visibly, and add labor. Maintenance workers, meanwhile, are paid too little — many are temporary hands on a daily wage — which makes it even harder to be sure the work is done by the book.

Nor is this only a maintenance problem. The reason a green space needs spraying at all, he told QDaily, is usually planted during construction. "Construction has no shortage of problems — bad planning, pests and disease carried in by people, unsuitable species brought in, and so on. Maintenance is often cleaning up after construction," he said.

A professional in the landscape design industry told QDaily that developers' dislike of native species has a money motive behind it: imported plants cost more. In February this year, a commentary in The Beijing News attacked the extravagance of "planting southern trees in the north" in urban greening, and called for the budgets and final accounts of greening projects to be made public.

Huang Yue, a postdoctoral researcher at Peking University's School of Life Sciences, says her greatest interest is getting ecological methods into urban greening. She studied landscape architecture from her undergraduate years through her doctorate, and has worked on the planning and design of landscape projects. A Chinese urban green space, she told QDaily, is planned, designed and then built; when construction is done the builder usually maintains it for a year before handing it to a maintenance company. The maintenance company never gets a say in the first three stages. What planners and designers are after, at bottom, is "tidiness" and "good looks" in the ordinary sense: flowers to look at in every season, a set share of evergreens, plants without pests or disease. Keeping the plants healthy and handsome means spraying on a schedule. Technical guidelines call in principle for low-toxicity and biological agents, but in practice nobody checks.

"Take Beijing's bad spring catkin problem," Huang Yue said. "It happened because rapid urbanization planted so many fast-growing species from the willow family. And wherever locust trees are planted too densely, it's easy for the locust looper moth — a moth whose larvae eat locust leaves — to take over." If the building stage had been done more sensibly, she argues, nobody would now be injecting the willows and poplars or spraying the locusts.

A Slogan: "Let the Weeds Grow"

Cui Xinting is a PhD candidate in the accounting department at the Capital University of Economics and Business, working on environmental auditing. She paid no attention to urban greening until 2015, when she happened to watch a Beijing university replace all of its turf. She then found that replacing turf is routine at Beijing's universities and in its public green spaces, and realized how much of the city's grass had never grown there on its own. That is when she started studying greening.

Those neat, good-looking, crew-cut lawns are all "cool-season" turfgrasses, she told QDaily, and all of them are non-native. They cannot take drought and need heavy watering; they neither hold soil nor keep moisture in it, which runs against the "sponge city" idea promoted by the Ministry of Housing and Urban-Rural Development. Having no biodiversity, they are easy prey for pests and disease, so spraying becomes unavoidable. Without insects and microorganisms to keep the soil alive, the ground beneath the turf goes barren and compacted, and fertilizer and nutrient solution become standard issue. This pampered grass has to be replaced every few years at best and every few months at worst, or it turns into public wasteland.

To change that, Cui Xinting argues, artificial turf should give way to hardier native weeds. She has boiled it down to a slogan: "Let the weeds grow."

The Jinbangyuan residential compound in Beijing's Changping district, she told QDaily, is one experiment in letting the weeds grow. When Jinbangyuan was built in 2001 it was planted with French Kentucky bluegrass at 200 yuan a square meter; by 2008 all of it had degraded. The property management company said fees had not gone up while replacing and maintaining the turf cost too much, and refused to replant. In 2015, the residents' committee, the residents and the property company began working together, sowing and tending drought-tolerant, attractive native wildflowers and grasses to a plan. They found this mixed plant community stood drought better and grew more vigorously, flowered earlier in spring and stayed in bloom longer over the year, suffered less from pests, needed no spraying — and did not run wild either.

As it happens, the China Biodiversity Conservation and Green Development Foundation (CBCGDF), which has filed one environmental public-interest lawsuit after another in recent years, put forward a "let the wild grasses grow" proposal of its own in 2016, hoping to protect plant genetic resources, protect insects and improve the city's water systems, while opposing the disorder of "planting southern trees in the north."

Oslo is letting the wild grasses grow too. According to a report in Britain's The Guardian last year, the Norwegian capital has since 2016 opened more than a dozen urban meadows planted with native wildflowers and grasses, and encouraged residents to turn their own garden lawns into meadows as well. The hope is that these become "insect corridors" through the city, bringing back bees and other insects and reversing a loss of biodiversity that has come with fast population growth. Protecting biodiversity is said to have become a central theme of Oslo's municipal planning.

Making Biodiversity the Standard

Huang Yue first put her interest in "ecological greening" to work on the Peking University campus. In 2016, on behalf of her school's Center for Nature and Society, she asked the university's landscaping office whether the areas richest in birds and plants could be managed in ways that respect biodiversity — no pesticide, no clearing away of fallen branches and leaves, so that organic matter goes back into the soil and habitat is created for plants and animals. She and her colleagues wrote the proposals into a Peking University Biodiversity Management Plan and handed it to the administration.

In 2017, Huang Yue's co-advisor, Peking University life sciences professor Lü Zhi, suggested she use the "small nature reserve" framework instead. A small nature reserve is a modest designation for places too small to meet the standards of a formal nature reserve but still worth protecting. The first appeared in Wuyuan, Jiangxi in 1992; in 1995 the State Forestry Administration spread the Wuyuan model nationwide, and as of last year there were 48,400 of them across the country. They usually start from ordinary people's own wish to protect a place, and the form the protection takes is flexible.

So Huang Yue and her colleagues proposed that the university set up a "Peking University Yanyuan Small Nature Reserve" across 42.5 hectares of campus. The university has held several review meetings on the proposal; approval is still pending. If it comes through, Huang Yue thinks, the Peking University campus could become a model for other universities and parks.

Another piece of Huang Yue's work could change how green spaces are built and maintained at the level of the rules themselves.

Since last year, commissioned by the Beijing Municipal Landscaping and Greening Bureau, she and her colleagues have been helping draft the Technical Guidelines for Evaluating Bird Diversity and Habitat Quality in Urban Green Spaces, due to be finished by the end of this year and now open for public comment online. After that she will help draft one or two more sets of technical guidelines, on restoring and managing biodiversity in green spaces. This will be one of China's earliest attempts to let "biodiversity" guide how urban green spaces are built and maintained. Huang Yue hopes the guidelines can be given some force — written into government tenders, for example. In Germany, she told QDaily, the national Federal Nature Conservation Act and the state-level Berlin Nature Conservation and Landscape Management Act both require urban greening to protect biodiversity, and it is time China's big cities considered the same.

Building Ecological Consensus in the Community

Liu Yuelai teaches in the Department of Landscape Studies at Tongji University. In June 2017, his talk for the ideas series Yixi struck a chord with a lot of people. In it he took mainstream landscape design apart: it costs a fortune, it damages the environment, and residents neither own nor really use what it produces. He then showed the audience what years of that thinking had produced — two projects his non-profit, Siyecaotang (Clover Nature School), has run in Shanghai's Yangpu district since 2014: Train Vegetable Garden and Chuangzhi Farm.

Train Vegetable Garden lies beside a branch of the Wusong–Shanghai Railway and covers 7 mu, about 4,700 square meters. Chuangzhi Farm is a narrow strip wedged between an old compound and a new one in Wujiaochang, covering 3 mu, about 2,000 square meters. Both had been public lots piled with construction waste for years. Once the government or the developer had commissioned it, Clover Nature School cleared the rubble, heaped fallen branches, leaves and other organic matter on the bare ground to bring the soil back to life, then slowly planted a mix of species — fava beans, rapeseed, blueberries, mulberries, herbs. They dug an irrigation channel at Train Vegetable Garden and built a rainwater collection and irrigation system at Chuangzhi Farm. Little by little, frogs, dragonflies, crayfish, light-vented bulbuls and blackbirds turned up.

So did people. More and more residents came by to look at the plants, do a bit of "farm work," or hear a talk on community building or organic farming in the community center made out of shipping containers. Sometimes the farm threw a "food party" with its own small harvest. Public green space stopped being a "green no-go zone" and became a public space that made community life richer.

Once those two projects had matured, and with Shanghai pushing "urban micro-renewal" these past two years, Clover Nature School moved into more than 30 residential compounds and schools, picking the patches with the worst vegetation and opening up miniature "community gardens" of about 200 square meters. They train residents and students to turn these corners into "hundred-herb gardens" carrying well over a hundred plant species through the year.

Liu Yuelai has also recently helped draft a standard: the Community Garden Habitat Certification System, launched jointly by Clover Nature School and The Nature Conservancy. Under it, Liu says, pesticides are banned outright. It also encourages returning fallen branches and leaves to the soil, using native plant species, and relying on plants' own self-seeding rather than bought commercial seed. And it encourages residents to do the gardens' work and management themselves — making kitchen-waste compost at home to feed the soil, for instance, and keeping outside inputs to a minimum.

Whether any of these values reach actual urban greening, though, will be decided by what city residents agree on. Even at Jinbangyuan, Cui Xinting told QDaily, some residents cannot stand the native grasses and have shouted for the weeds to be cut down and doused with herbicide. Huang Yue has learned much the same on the job: greening departments genuinely do want to maintain green spaces ecologically, and sometimes spray anyway, with no enthusiasm for it, simply because residents with little tolerance for insects have complained.

Liu Yuelai hopes his certification system can become a standard that housing compounds, parks, community gardens, residents, landscape designers and others take up voluntarily, out of shared agreement — though "if the government wants to use it, that's fine too." Still, he believes that "if biodiversity doesn't become part of residents' values and way of living, no change will last." That is why, in this system, community building counts for as much as biodiversity does.

So That Spring Does Not Fall Silent

It rained in Dalian on July 8, and Sun Kang guessed the plane had not come. She had no time to dwell on it: she was out all afternoon. At noon the Dalian Forest Zoo had called — a resident had picked up an injured Oriental scops owl chick on the road and brought it in, and they wanted her help treating it. Her other role is founder of the Lüshunkou District Wild Bird Protection Association in Dalian. She has spent ten years protecting wild birds, once working with the government to bring the bird nets on Mount Laotie, part of the "thousand-year bird route," under control, and along the way becoming an expert at rescuing birds in trouble.

Dalian sits on one of the world's eight great bird migration routes, she told QDaily, and is home to more than 300 species of wild birds. It was early summer, the season when large numbers of fledglings start learning to fly, so there are always young birds that lose their footing and need help. She agreed to take the scops owl home and release it once it recovered. On the drive back with the owl, the zoo called again: two magpie chicks had been found in the middle of Liansheng Street. She and a student rushed over, found them, and put them back up in a tree; their parents found them again soon after.

Before going to the zoo she had written the staff a proposal setting out the aerial-spraying issue, pointing out that the zoo itself lies inside this round's spray zone, and suggesting the two sides work together to establish how far the spraying actually reaches and to monitor its effects on mammals and birds.

Sun Kang said she had never given a thought to what pesticides do to the urban environment before. Now it is a beginning. She wants to do some "real, solid research" and find out exactly what aerial spraying does to the environment, to animals and to people.

"Since it's already been sprayed, we should take the chance to study it," she said.

Homepage cover image:

chuttersnap on Unsplash; app-version inside-page image: Sun Kang; desktop-version inside-page image: Jiang Yifan/QDaily