Agricultural Pollution Livestock Wastes Figure 1: Farm Animals in Tight Quarters Sources: fowl: © blickwinkel / Alamy Stock Photo; cows: Don Despain / Alamy Stock Photo; pigs: © Edd Westmaccott / Alamy Stock Photo Why Care about Livestock Wastes? policy makers need to be aware of the following. First, The livestock sector is a major and growing source of changes in management practices can make a signifi- pollution across the world as rising global demand for cant difference when it comes to controlling pollution animal products including beef, pork, poultry, and dairy within different livestock systems, and certain technical products is leading livestock operations to not only ex- solutions can be adopted cost-effectively or with public pand their output, but also to concentrate spatially, in- sector support. Industrialization, in this respect, opens tensify, and separate from plant agriculture. Although new possibilities for monitoring, regulatory control, and livestock system outputs are growing faster than their the adoption of technology. Second, while demand for spatial footprint—as managed grazing is giving way to animal products reflects diverse sociocultural realities confined, grain-based feeding—this pattern of develop- such as food preferences and social signaling (for ex- ment has major drawbacks and this note focuses on those ample, prestige), high levels of consumption are neither related to animal wastes.1 In parts of both the developed desirable for public health or the environment, nor an and developing world, animal wastes have become a inevitability.2 There is room to shape this growing sector leading source of surface and ground water pollution as in a way that modulates its breadth, its geographic con- they are a major vector of unwanted nutrients, and also centration, and its intensity. carry pathogens, antibiotics, hormones, heavy metals, other minerals, and pesticides. Through the release of particulate matter and other air pollutants, they are also a Nature and Magnitude of the Problem cause of foul odors, haze, acid rain, a loss of soil fertility, Livestock systems occupy roughly one-third of the plan- and air quality-related disease, while their potent green- et’s ice-free terrestrial surface area and, as of 2014, sup- house gas emissions contribute to climate change. plied 17 percent of available food calories and accounted Looking forward, if the world remains on course to for over half of global agricultural GDP. Far from being roughly double meat and dairy consumption relative static, the sector is rapidly gaining ground in the devel- to 2000 levels by mid-century, livestock production will oping world—particularly Asia and Africa—where it is continue to industrialize and expand. Thus faced with among the fastest growing subsectors of the agricultural the rise and transformation of the livestock subsector, economy (see Figure 2). 1 Looking beyond animal wastes, the expansion of livestock production—in both extensive and intensive systems—is the leading cause of deforestation worldwide and a major contributor to land degradation. In Latin America, both grazing and field crops are encroaching into sensitive ecosystems, including the Amazon Forest. 2 From a health perspective, while some studies show that the introduction of animal products into diets can palliate pro- tein and vitamin deficiencies, and others note that animal products provide important nutrients, the consumption of animal products (animal protein, fats, hormones, and so on) is also associated with increased risk of cardiovascular disease, diabetes, and certain leading forms of cancer. For this reason, nutritional guidelines consistently recommend higher intakes of whole, plant-based foods, while some recommend lower intakes of animal-based ones. In addition, livestock products are susceptible to pathogen contamination and can vehicle zoonotic diseases. See multiple citations in references. This note was written by Emilie Cassou. Full references and acknowledgments are available online. Agricultural Pollution Livestock Wastes Box 1. Livestock Sector Overview The livestock sector produces a variety rising number of poultry birds, meat, dairy, eggs, fats, and honey—and of products from domestic, terrestrial (chickens, ducks, turkeys, geese, and non-food products such as wool, silk, animals. Though ovines, bovines, and guinea fowl), and large numbers of hair, hides, fur, bone, wax, and so forth. swine (that is, sheep and goats, cattle horses, mules, asses, camels, rabbits, Livestock are also used as draught and buffalo, and pigs) dominate the bees, and silkworms among others animals and for recreational purposes. sector by far in terms of population (see figure 3). The sector’s outputs size, livestock also include a rapidly include both food products—mainly While traditional livestock systems are far from be- individually, can be small to mid-size and moderately ing impact-free, the industrialization of animal agri- intensive in nature. From a big picture perspective, in- culture—a phenomenon observed across regions—is a dustrial livestock systems are contributing to the glob- game changer. With it, animal wastes tend to go from al imbalance in nitrogen and phosphorus cycling, two being a valued agricultural resource—a bearer of soil domains in which human activity is testing the planet’s fertility—to a costly waste stream and multi-hazard pol- biogeochemical boundaries.3 lutant. Concentration in particular makes it more like- ly for fecal nutrients to exceed local capacity to safely Impacts absorb these, for fecal pathogens to cause disease, and Under current management practices, livestock wastes for pesticides and antibiotics to be used preventively to are contributing—often in high proportion—to water, ward off houseflies, other pests, and diseases. The pol- soil, and air pollution, and concentrated operations are luting effects of industrialization are usually directly at- generating especially acute problems in their vicinity. tributable to poor livestock waste management practices These include the eutrophication of surface waters, the such as the flushing of untreated waste or the collection contamination of drinking water, antimicrobial resis- of manure in leaky or open-air lagoons, as well as to op- tance, particulate pollution, and a loss of soil fertility, erations’ geographic siting. In many developing coun- leading to ecosystem disruption, a loss of farm produc- try contexts, animal rearing activity has formed rings tivity, heightened food safety risk, and disease. A full 86 around cities, causing major pollution problems by vir- percent of global effluent (in kilograms of fecal pollution tue of their geographic concentration and proximity to per year) is attributed to livestock, and in surface wa- urban dwellings, even though these operations, taken ters, the flow—or deposition—of fecal nutrients (mainly Figure 2: Live Animals by Region, 1961–2014 Figure 3: Live Animals by Type, 1961–2014 Billions Billions Millions (poultry) 2.5 2.5 25 2 2 20 1.5 1.5 15 1 1 10 .5 .5 5 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 ■ Asia ■ Africa ■ Americas ■ Europe ■ Oceania ■ Cattle & buffalo ■ Sheep & goats ■ Pigs ■ Horses, asses, mules, camelids ■ Other Source: Based on FAOSTAT data. ■ Poultry (left axis) ■ Poultry (right axis) 3 The cycling of phosphorus occurs on a geological timescale, such that the mining of phosphorus—80 percent of which is used to make fertilizer—is drawing down known reserves of the mineral and contributing, through accumulation in aquatic environments, to widespread eutrophication. In the case of nitrogen, organic waste management practices that inhibit plant and animal nitrogen from feeding their regrowth, and the addition of nitrogen into the food chain in the form of synthetic fertilizer, are energy-intensive and sources of both air and water pollution. Agricultural Pollution Livestock Wastes ammonia, organic nitrogen, and phosphorus) is a ma- Figure 4: Backyard Pigs Amidst Homes in Peru jor cause of eutrophication. This phenomenon can lead to the spread of toxic algae and hypoxic zones in which nothing can live. In China, where these are growing problems, 38 percent of nitrogen and 56 percent of phos- phorus in surface waters are attributable to livestock. In the United States, livestock manure is second only to fertilizer use as a source of Mississippi Basin nitrogen, which (with phosphorus) is fueling the dead zone that now stretches across 16,800 km2 of the Gulf of Mexico. Livestock manure and poultry litter account for about half the nutrients entering the Chesapeake Bay, a major U.S. estuary. In addition to harming human health and biodiversity, eutrophication can prove costly to the utili- ty, beverage, tourism, and fishing industries. The improper management of animal wastes also bears responsibility for the contamination of drinking water with nitrates, pathogens, hormones, and some- times pesticides. These can also taint food products Source: © Pilar Olivares/Reuters. directly, affecting food safety and detracting from agri- Note: Pamplona Alta shantytown in Lima, Peru, on September 30, 2011. cultural trade. Pathogens and zoonotic diseases such as E.coli, listeria, salmonella, giardia, influenza, foot and fertilizer, its over-application leads to soil acidification, mouth disease, bovine spongiform encephalopathy, and as do its gaseous contributions to acid rain. Together others, are known for their acute and sometimes lethal with the build-up of heavy metals used in feed, its ex- effects. Other pathogens and growth hormones, by con- cessive use or mismanagement can lessen land fertility trast, can provoke cancers, endocrine disruption, and (increasing fertilizer use and pollution). Manure being other ailments with a late onset or chronic pattern that heavy and costly to transport to increasingly distant can sometimes blur the agricultural origins of these. crop fields, however, it is progressively being foregone Pesticide effects fall into both categories. Meanwhile, as a source of soil organic matter, even as soil—a vir- the prophylactic administration of antibiotics to ani- tually nonrenewable resource—is being mined unsus- mals held in tight and sometimes unsanitary quarters, tainably. particularly when practiced on a wide scale, paves the way for hazardous and costly antibiotic resistance. In Drivers the United States, livestock consume some 87 percent The emergence of livestock waste as a pollution problem of antibiotics. In 2016, the United Nations recognized in a widening part of the world is closely intertwined antimicrobial resistance as one of the biggest threats to with urbanization, income growth, and the rising de- global health, and elevated the issue as it has HIV, Ebola, mand for animal products that has accompanied this de- and non-communicable diseases in the past. velopment pattern. Industry has effectively risen to the Turning to air pollution, animal wastes, when they task of delivering ever-larger quantities of (affordable) are stirred up or decompose—particularly when they animal-based foods to urban dwellers by concentrating are concentrated—release a range of noxious gases and geographically around cities and industrializing in or- fine particles (or precursors to these) that do more than der to realize economies of scale and minimize trans- cause unpleasant smells and haze. Manure accounts, for portation costs. Indeed, transportation costs loom large example, for around one-third of global emissions of in an industry that needs to move bulky feed inputs ammonia, a precursor to acid rain and particulate pol- and highly perishable products—often relying on un- lution. And though animal wastes are not their primary derdeveloped or aging transportation infrastructure in cause, both have clear links to respiratory, cardiovascu- emerging economy contexts. The weak enforcement or lar, and other forms of disease, accelerate building and absence of regulations pertaining to farm siting, inten- infrastructure corrosion, and harm soil fertility. Manure sity, or waste management, meanwhile, have generally management also results in significant emissions of ni- allowed private investment in this growing subsector to trous oxide and methane, powerful greenhouse gases discount the costs of negative, pollution-related exter- linked to climate change. Particulate pollution, for its nalities. Manure management can represent a signifi- part, can accelerate near-term and local climate change. cant share of operating costs (for example, 10–15 percent From a crop farming perspective, the concentration in Northern Europe), and improving these from an envi- of manure sources is creating problems related to both ronmental perspective can weigh on producers’ bottom its overuse and underuse. Although manure is a natural line. Agricultural Pollution Livestock Wastes What Can Be Done? comes can be expected if producers are legally or com- While the industrialization of livestock operations is mercially barred from operating, activating insurance, or creating and magnifying certain waste-related pollu- accessing given markets without adopting best available tion problems, it is also opening new avenues for pol- control technologies or performing in alignment with lution control. Industrial systems, particularly as they these. The Netherlands, for example, imposes limits on increase in size and consolidate, are more easily traced the amount of nutrients farms may generate and spread, and controlled than small, dispersed, and informal (that and the number of heads they raise, per hectare of land. is, backyard) activities—though their influence over reg- To limit ammonia emissions, it also requires farms to in- ulators may also grow. And from technical and financial ject manure into the soil when applied to grasslands or standpoints, they may have greater options and capaci- maize fields. Subsidized loans and credit guarantees can ty when it comes to adopting mitigation technology (or encourage producers to upgrade their on-farm technol- even improving efficiency). This is namely due to econo- ogy, as can performance-based incentives that facilitate mies of scale in manure management. maintenance and upkeep. For multiple years, the Dutch One path to mitigation involves the pursuit of live- government financially supported farmers to invest in stock system efficiency within concentrated systems. manure storage facilities and other waste disposal tech- This may mean selecting breeds, feeding practices, nologies. It also established a national manure bank to housing conditions, or cleaning protocols that maximize transport excess manure to crop farms where it could be feed conversion efficiency and reduce effluent per unit used more safely. of milk or meat. This approach can marginally improve The removal of counterproductive incentives, such the environmental performance of existing industrial as energy,4 production and other subsidies which dis- systems and align well with business motives. It can be proportionately benefit the most intensive or polluting supported through investments in research, extension, systems, can be an another effective strategy in some and infrastructure, and indirectly through water pric- cases. In many contexts, improvements can also come ing or other incentives that encourage resource-use effi- from better enforcement of existing standards, be they ciency. Such policies can be nearsighted, however, if by mandated or voluntary. Publicizing requirements and encouraging further concentration they increase overall incentives can provide an opportunity to raise farmers’ pollution. awareness of different technologies, management prac- Still within industrial systems, a second approach in- tices, and their impacts. These strategies are more likely volves the adoption of pollution control practices and to be effective, however, if they are designed with and technologies and the phase-out of those which are most around farmers’ perceptions, constraints, and needs polluting. Examples of mitigation technologies include from the beginning. This can be seen in the relative suc- the use of buffer crops or holding ponds to absorb nu- cess of Dutch flagship farms—real farms that exceed trients and filter out water pollutants; the adoption of average environmental performance—which have been lagoon covers to contain volatile compounds; anaerobic used to demonstrate what can be achieved and calibrate digestion with methane capture and use; ammonia re- national environmental requirements. covery and sale as fertilizer; and biological conversion of A third and more transformational path to mitigation nitrogen to less reactive forms. Other measures include is based on changing the geographic distribution and changes in feed that reduce nitrogen and heavy metals concentration of animal agriculture, or in other words, in manure, and the construction of animal quarters that engaging in spatial planning to use landscape resources require less antibiotics to control outbreaks. This ap- more favorably. Livestock operations can be distanced proach generally requires site-appropriate technologies from cities and fragile ecosystems, sited closer to plant to be developed and absorbed into operations. agriculture (though this can lead to cross-contamina- Meanwhile, their adoption can be stimulated by be- tion risk), dispersed in space, and limited in size or in- ing required—explicitly or implicitly—by such things tensity—so long as this does not cause them to further as licensing, market access, certification and labeling, encroach on natural landscapes. In this case, land-use taxation or subsidies, and financing (for example, in- planning and regulations including zoning rules can surance, credit, and guarantees). Taxing the disposal be put to task, alongside economic incentives and in- of concentrated manure, its emissions, or other exter- frastructure investments. In Thailand, for instance, the nalities, for example, can encourage farms to mini- dissuasive taxation of operations within a 100 km radi- mize these voluntarily; so can paying farms for these us of Bangkok helped to spatially disperse these, as did outcomes directly. This can be achieved by purchasing the construction of a new slaughterhouse a few hundred verified emission reductions (for example, methane), or kilometers outside the city. Though less direct, invest- paying a price premium for a labeled product (for exam- ments in road and logistics infrastructure can enable ple, growth hormone- and antibiotics-free). Similar out- 4 Incentives for biogas energy, however, can act as an incentive for improved waste management. Agricultural Pollution Livestock Wastes more distant livestock farms to supply cities. Figure 5: Venture Funding is Flowing into the A complementary path to mitigation involves curb- Development of Meat Alternatives ing production growth by curbing the demand for live - stock products in food-secure contexts. This can be pur- sued through interventions focused on, inter alia: ➤➤ Changing social norms and preferences (e.g., through cultural and role model strategies such as the enlistment of celebrity Arnold Schwarzeneg- ger to dissuade meat consumption in China,5 U.S. “checkoff” program-style food marketing cam- paigns, social marketing); ➤➤ Raising consumer and medical professional aware- ness (e.g., broadcasting of dietary health guidance by government, insurance companies, health education non-profits); ➤➤ Habitual behavior (e.g., employer wellness pro- grams, cafeteria choice architecture and other food environment changes studied by Cornell Universi- ty’s Brian Wansink, “Meatless Monday”-style cam- paigns, interventions to increase availability of and consumer access to fresh fruits and vegetables); and Source: © Beyond Meat. ➤➤ Economic incentives (e.g., food-related taxes and sub- sidies, other interventions that influence food prices, public dietary guidance (for example, in Brazil, the Unit- food safety nets and income support programs—or ed States, and the Netherlands). In the United States, this insurance and retailer reward programs—that privi- has stimulated flows of venture capital into the devel- lege specific food spending patterns). opment of cell-cultured meat and plant-based meat sub- stitutes that are able to gain consumer acceptance (see Growing evidence surrounding the health benefits figure 5). Regardless of the approach, robust monitoring and environmental co-benefits of whole food, plant- of livestock systems practices, its pollutants, and their based diets are increasingly being incorporated into impacts are the starting point for mitigating these. 5 http://wildaid.org/news/james-cameron-arnold-schwarzenegger-speak-out-reduced-meat-consumption.