None of this is dramatic. The block isn't going to put you in hospital on its own — cross-contamination from raw poultry does that, and the block is one input among several. But it is one of the easier inputs to close: free, sixty seconds of habit, ten minutes a month. The bonus you weren't expecting is the knife itself, which stops dulling and pitting from wet sheathing and starts holding the edge you bought it for.
A knife slot is a near-perfect microbial incubator and it's right there on your counter. Deep, narrow, dark, no airflow, lined with wood that quietly absorbs moisture. You wash the knife, give it a flick to shake off the water, slide it home blade-down. The film of water on the steel transfers to the slot walls. Crumbs from the cutting board ride down with it. Below the visible part of the blade, in the part of the slot you'll never see again, that mixture sits in the dark at room temperature.
That is what bacteria and mold want. Within days a biofilm can form in the deep cracks and machining marks of the wood — a slimy bacterial city that resists casual wiping and survives ordinary cleaners better than free-floating cells do (Carpentier 1997). The headline pathogens that show up on home-kitchen swabs of these surfaces — E. coli, Salmonella, Listeria, Staph aureus, plus a chorus of yeasts and molds — all do well in exactly this environment (NSF 2013).
The reason this matters past "ew" is the next prep session. You pull the knife back out, run it under the tap, start slicing a tomato for sandwiches. Whatever was living on the slot wall is now on the blade, and from the blade onto the tomato — the same cross-contamination route that turns raw-chicken juice into someone's Tuesday-night gastro (Luber 2009). The block didn't infect the food directly; it gave yesterday's contamination a warm, wet place to wait.
What the swabs actually find
NSF International's 2013 household germ study sent swab kits home with twenty volunteer families and tested fourteen common kitchen items. Knife blocks landed seventh on the list of items carrying clinically relevant microbial loads. All fourteen items came back positive for yeast and mold; six categories — the knife block among them — came back positive for coliforms, E. coli, Salmonella, Listeria, or Staphylococcus aureus at concerning levels (NSF 2013). This isn't a laboratory inoculation; it's twenty real kitchens swabbed once. The numbers tell you how common the contamination is, not how often it makes someone sick.
For the illness arrow, you have to step one layer out, to the well-mapped cross-contamination route from raw poultry. The CDC puts Salmonella and Campylobacter together at roughly three million foodborne illnesses a year in the US (Scallan et al. 2011), with chicken the single largest source category for Salmonella (IFSAC 2021). The standard quantitative risk-assessment view of campylobacteriosis from poultry in well-resourced kitchens is that cross-contamination — knife, board, hands, surfaces — is the dominant route, ahead of undercooking (Luber 2009). Your knife and the block it lives in sit on that route.
What no one has done is the trial that would tie this all together neatly — randomise a thousand households to "dry your knife, brush your block monthly" versus the status quo and count gastroenteritis cases for a year. You can see why it's not been run. So the call has to lean on the mechanism plus the swab studies plus the cross-contamination quantification, not on a single clean endpoint.
And the knife itself is rotting
The hygiene story tends to get all the attention, but for most people the more visible cost of bad block habits is the edge of the knife. Kitchen steel is alloyed for hardness and edge retention, which makes it more vulnerable than your fork or spoon to pitting corrosion. Stainless protects itself by holding an invisible chromium-oxide film on every exposed surface — but that film only reforms in air. Under a wet film of salty, slightly acidic food residue (a bit of tomato, a streak of citrus, traces of salt from the cutting board) the protection can't rebuild, and the iron underneath slowly rusts in microscopic spots (Cliver 2006).
A wet blade in a damp slot is the textbook setup for that process. Each wet sheathing is another small window of pitting along the edge. Six months in, the bolster has a brown speckle and the edge feels suddenly dull — not because the cutting wore it out, but because the corrosion ate the cleanly-ground micro-edge that did the actual slicing. The dishwasher accelerates the same story for the same reasons, plus the bonus of being banged around against other utensils. This is why every quality knife maker's care card says hand-wash, dry immediately, store dry: the protocol is genuinely correct, not marketing.
The actual practice
Two habits, one daily and one monthly. Neither takes real time.
If you're replacing the block, get a better geometry
The slotted wooden block exists because it looks good on a counter. From a hygiene-and-edge standpoint, almost any other storage geometry is better, because almost any other geometry exposes the blade to air instead of sealing it in a damp tube. If the current block is at end-of-life or you're setting up a new kitchen, the choices worth knowing:
- Magnetic strip on the wall. Every surface of the blade dries in open air; nothing is sealed in moisture; cleaning is a wipe with a damp cloth. The catches are real but small: knives at grab height are a hazard if small children are around, and mounting too close to the cooktop puts a film of cooking grease on the blades.
- In-drawer knife tray. A wooden or plastic tray that holds blades in shallow open channels inside a drawer. Out of sight, no slot to clean, blade air-dries because the channel is open. Costs a drawer.
- Universal bristle block. A block filled with vertical plastic rods that part for any blade. Easier to clean than slots (pull the bristles out, wash them in the sink) and doesn't lock a blade against a specific slot geometry, but the bristles can still trap moisture if you don't dry the knife.
The pattern: any geometry that lets air to the blade and lets you see what you're cleaning beats a closed slot. Whichever one you pick, drying the knife before storage is still the load-bearing step. A wet blade on a magnetic strip is just a wet blade with better airflow.
What people get wrong
- "Wood is antibacterial — the block is self-cleaning." The famous finding here is real but it's about wood as a cutting surface in open air: a clean wooden board pulls a contaminating drop of chicken juice down into the grain within minutes and the bacteria die over hours as the wood dries (Ak et al. 1994). A knife slot is the opposite microclimate — a sealed damp tube with no drying happening. The wood-as-killer effect needs air. The slot doesn't have any.
- "The dishwasher sanitizes the knife, so it's fine." Heat kills pathogens, yes. It also bathes the edge in chloride salts and alkaline detergent for an hour, bangs the blade against other metal, and finishes with a hot-then-slow cool that encourages corrosion. Hand-washing in hot soapy water and immediately drying gets you the same hygiene without trading away the edge.
- "A quick rinse between the raw chicken and the salad is enough." A cold rinse reduces but does not clear contamination from a serrated edge, a wet handle joint, or any knife-scarred surface. Soap, hot water, and ideally a separate board for raw protein is what actually breaks the chain.
- "If I can't see any crumbs in the slot, it's clean." Biofilm at the bottom of a deep slot is invisible to the naked eye. Shine a phone flashlight straight down a chef's-knife slot in a block that has never been deep-cleaned and you'll usually find what the casual inspection didn't.
There's nothing unsafe about owning a slotted wooden block if you dry the blade and clean the slots. The one place to raise the bar is households with an immunocompromised member — someone on chemotherapy, a transplant recipient, advanced HIV — or older adults at the conservative end. The infectious dose for Salmonella and Listeria is meaningfully lower in those populations and a hospitalisation hits harder. For those kitchens, a magnetic strip or an in-drawer tray plus rigorous monthly cleaning is the right floor; the slotted block is keepable but not the path of least resistance.
What you keep losing if you don't fix this
None of this is dramatic — that's the honest framing. The block isn't a hospitalisation in waiting on its own. What it is, is a steady drip.
The drip on the knife: six months in, the bolster has a brown speckle you scrub at with steel wool and almost get off. A year in, the edge that used to glide through a tomato is suddenly skating across the skin, and you tell yourself it needs sharpening — which it does, but earlier than the steel would have asked for. Two years in, your good chef's knife needs a professional regrind to lift the pits out of the edge. The $200 tool ages like a $40 tool.
The drip on the kitchen: the bottom of the chef's slot is a damp pocket where yesterday's chicken-juice bacteria spent the night warm and undisturbed, and rode the blade back out to today's tomato. The contribution of any single block to any single illness is small and unmeasured — but cross-contamination from raw poultry is one of the largest preventable foodborne-illness routes in a home kitchen (Luber 2009), and the block is a stop on that route you'd never close by accident.
And the drip you don't quite name: the faint sour smell when you open the cutlery drawer, the dark ring in the bottom of one slot you noticed once and didn't think about again, the mystery rust speckle along the back of a knife you only use at Christmas. These are the things the friend visiting your kitchen wouldn't say anything about. They're a low background hum of "the room is not quite clean" that you stopped hearing because it's been there a year.
What changes when you start
Day one: the block is empty, upside-down on the rack, and the knives are on a tea towel. You feel slightly silly doing this. It takes ten minutes.
Week one: the daily drying becomes muscle memory. You barely notice it. You haven't noticed any difference in the kitchen either — because what's changed is the absence of a process you couldn't see.
Month one: you do the second cleanout. There's already noticeably less to tap out of the block. You do start to notice the knife, though — the edge feels the same as it did a month ago, which is the first time in a long time you could say that. Nothing has dulled in the background.
Year one: the bolster is clean. No speckle. No mystery rust on the back of any blade. You're sharpening the chef's knife maybe twice a year instead of "whenever it stops cutting," and the steel underneath is taking the edge cleanly because the micro-corrosion isn't eating it. The block, opened up, smells like wood instead of like the back of a damp cupboard. Quiet wins, but they compound — the kitchen is a less hospitable place for the small bacterial ecosystem it used to host, and the tool you paid for is doing the job you bought it to do.
Cutting-board hygiene is its own entry — different surface, different scrub procedure, different wood-vs-plastic call. So is sponge and dishcloth contamination, which is a bigger reservoir than the block on most kitchens' swab counts. Knife sharpening — how often, hone versus stone, professional regrind — sits alongside this; care and sharpness are two halves of the same tool. And the older cross-contamination basics — separating raw meat boards, washing hands after handling raw poultry, not rinsing chicken in the sink — are the upstream practices the block-hygiene work makes more effective.
Substance and claimed effects
This entry covers the hygiene of kitchen knives and the slotted wooden blocks they commonly sit in: the moisture and food residue trapped in dark, unventilated slots, the bacterial and fungal growth that follows, the cross-contamination route back onto the blade (and from there onto cooked food), the corrosion of the edge under repeated wet contact, and the cleaning, drying, and storage practices that close those loops. The substance is small but the consequence chain is real — block contamination intersects with the largest preventable foodborne-illness route in the home kitchen (cross-contamination from raw poultry and meat). Claimed effects across the catalogue dimensions: meaningful reduction in foodborne illness risk (longevity, health_short_term), a tangible reduction in the slow rust and edge dulling of carbon and stainless blades (cost_burden offset over years), and removal of a low-grade mold/yeast reservoir from one corner of the kitchen.
Evidence by addressing question
Mechanism
The knife block is a near-perfect microbial incubator: dark, deep, narrow slots with poor airflow, into which a still-damp knife is inserted blade-down after washing. Residual water and food traces (proteins, fats, sugars from the cutting board) collect at the bottom of each slot. Bacteria adhering to the wet blade are deposited along the slot walls; biofilms then form in the deep cracks and machining marks of the wood, where they resist routine wiping and survive disinfectants longer than free-floating cells (Carpentier 1997). The same biofilm-in-cracks mechanism is documented on cutting boards and other porous food-contact surfaces, and is the reason "surface clean" and "microbially clean" are not the same thing.
Cross-contamination from raw poultry juices is the dominant pathway by which block contamination becomes illness. The kitchen route is well-mapped: bacteria from raw chicken transfer onto the cutting board and knife at preparation; if those utensils contact ready-to-eat food (salad, cooked meat, bread) without re-washing, the pathogens transfer again (Luber 2009). A knife block adds a temporal arm to that route: if a partially washed, still-damp blade is sheathed in the block, surviving bacteria proliferate overnight in the moist slot and re-load the blade on its next use (Ak et al. 1994).
On the edge: kitchen steel is alloyed for hardness and edge retention rather than maximal corrosion resistance, which makes it more vulnerable to pitting from prolonged contact with chloride ions (salt residue), organic acids (citrus, tomato, vinegar), and alkaline detergents. The protective chromium-oxide passivation layer reforms in air but cannot reform under a film of wet food residue; each cycle of wet sheathing in a dirty slot is an opportunity for sub-microscopic pitting along the edge, which both rusts and dulls the blade.
Evidence
The NSF International 2013 Household Germ Study swabbed 14 common kitchen items across 20 volunteer households. Knife blocks ranked seventh on the list of items carrying clinically relevant microbial loads; all 14 items (100%) tested positive for yeast and mold, and six categories tested positive for coliform, E. coli, Salmonella, Listeria, or Staphylococcus aureus at concerning levels — knife blocks among them (NSF 2013). The study's methodology is observational (household swabs, not controlled inoculation), so the numbers describe real-kitchen prevalence, not transfer rates.
Cross-contamination from raw poultry is the load-bearing illness mechanism this entry feeds into. Experimental kitchen simulations using the same knife and cutting board to prepare raw chicken and then a ready-to-eat item, without intervening wash, find Salmonella recovered from 50% of knives and ~67% of cutting boards in the post-prep swab, with significant transfer onto the salad ingredient (Trang et al. 2022). Quantitative microbial risk assessments converge on cross-contamination (rather than undercooking) as the dominant kitchen risk for campylobacteriosis from poultry in well-resourced countries (Luber 2009). The CDC's burden estimates put non-typhoidal Salmonella and Campylobacter together at roughly 3 million foodborne illnesses per year in the US (Scallan et al. 2011); the IFSAC tri-agency source attribution attributes the largest share of Salmonella illnesses to chicken and other meat/poultry combined (IFSAC 2021). The knife and block sit on this pathway.
On material choice: the foundational Ak/Cliver/Kaspar work at Wisconsin-Madison contaminated new and used wood and plastic cutting boards with E. coli, Salmonella typhimurium, and Listeria in chicken juice; bacteria inoculated onto wood were absorbed within 3–10 minutes and could not be recovered, while bacteria on plastic persisted at recoverable levels and multiplied overnight, especially in knife-scarred high-density polyethylene (Ak et al. 1994). A follow-up review reiterated the finding and noted that knife-scarred plastic surfaces are very difficult to disinfect, while wood's absorptive behavior pulls bacteria away from the surface in a way that prevents re-transfer onto a knife (Cliver 2006). The relevance to a knife block: the same wood-absorption finding does not extend to a slot that holds a damp blade — the contact area is small and the slot itself becomes a microclimate. Wood does not sterilize what is sealed inside a wet slot.
Protocol
The shape of effective protocol is well established by food-safety guidance, even where formal RCTs are absent (the comparator — a wet, sheathed knife — is too obviously the worse arm to ethically run as a controlled trial):
- Dry the blade fully before sheathing. Wipe with a clean towel until no visible moisture, then air-dry on a rack for several minutes. The block does the rest of the drying poorly; the blade does it well in open air.
- Empty and clean the block periodically. Invert and tap out crumbs; brush slots with a bottle brush or pipe cleaner; wash with hot soapy water; rinse; air-dry inverted on a rack for 24–48 hours before reusing. Once-monthly is the routine; once a quarter is the minimum.
- Hand-wash knives. Soap, hot water, dry immediately. Dishwasher exposure compounds two harms — prolonged wet residence and chloride/alkaline detergent attack on the edge — and is the standard recommendation against from every quality knife maker.
- Storage geometry matters. Magnetic strips, in-drawer slot trays, and universal-bristle blocks all expose the blade to air and let it dry rather than sealing it wet. Slotted wooden blocks are the worst geometry by hygiene; they are kept for aesthetics and counter convenience, not for sanitation.
Contraindications
Few. Wooden blocks are not unsafe to own if dried-blade-only is honored. Households with immunocompromised members (chemotherapy, transplant, advanced HIV) sit at the conservative end — the lower infectious dose for Salmonella, Listeria, and E. coli in that population justifies higher-rigor storage (magnetic strip, in-drawer tray with regular cleaning) and treating cross-contamination prevention as non-optional. Older adults skew the same direction.
Misconceptions
Several worth naming:
- "Wood is antibacterial, so the block is self-cleaning." The Cliver finding is about wood as a cutting surface in open air; absorbed bacteria die over hours as the wood dries. A slot holding a wet blade is not a drying surface — it is a damp sealed niche, the opposite microclimate (Cliver 2006).
- "The dishwasher sanitizes the knife." Heat does kill pathogens, but the dishwasher's salt-and-alkali chemistry pits the edge, the high-pressure spray bangs the blade against other utensils, and the hot final cycle followed by slow cooling encourages corrosion. Hand-washing followed by immediate drying achieves the same hygienic outcome without trading away the edge.
- "Rinsing the knife between cutting raw and cooked is enough." A cold rinse reduces but does not eliminate transferable contamination on a serrated edge, on a wet handle joint, or along a knife-scarred surface. Soap, hot water, and a dedicated board for raw protein is the actual standard.
- "If I can't see crumbs, the slot is clean." Mold and biofilm at the bottom of a deep slot are visually inaccessible. The pulled-out drawer test — slide the block apart if it disassembles, or shine a phone light down each slot — usually reveals what the casual inspection missed.
Failure modes
The two failure modes in practice are shortcut sheathing (a still-damp knife goes in the block out of speed) and never-cleaned blocks (the slot has not been emptied since purchase). Both are common; both are quietly fixable. A third, rarer mode is treating the magnetic strip or in-drawer tray as a sanitation upgrade while still failing to dry the blade — the geometry helps but does not make a wet blade safe. Drying is the load-bearing step regardless of where the blade ends up.
Practicalities
Cost: zero for the existing block plus a brush; under $30 for a magnetic strip replacement; $20–60 for an in-drawer tray. Effort: 60 seconds of drying per use, 10–15 minutes of block cleaning per month. Time-of-day: the cleaning is end-of-day, not mid-cook. The slot-brush is the only specialist tool; a long bottle brush, a baby-bottle brush, or a clean pipe cleaner all work.
Stakes
The proximate stake is a small but real ongoing contribution to foodborne illness risk in the home — gastroenteritis from Salmonella or Campylobacter, occasionally severe in older adults, infants, or immunocompromised members of the household. The distal stake is the slow ruin of a kitchen tool: a chef's knife pitted along the edge from wet residue and dulled from the same micro-corrosion is unpleasant to use and eventually needs professional regrinding or replacement.
Payoff
The wins are quiet rather than dramatic: a knife that holds its edge longer between sharpenings, no mystery rust speckles to scrub off, a kitchen with one less low-grade microbial reservoir, and a measurable (if small) downward shift in the household's cross-contamination risk. Onset is immediate for the edge and the slot-mold; the illness-risk reduction is invisible because it is the absence of a future event.
Out-of-scope
Cutting-board hygiene as a topic warrants its own entry (different surface, different decision tree, different scrub procedure). Sponge and dishcloth contamination is a related but distinct reservoir. Sharpening protocol — frequency, honing rod versus stone, professional service — is its own subject. Knife metallurgy and steel choice (carbon vs stainless, hardness vs corrosion tradeoffs) belongs in a buyer's-guide entry, not this one.
The credibility range
Optimist case
The mechanism is direct, the swab evidence is consistent (NSF 2013 is the most-cited but the finding replicates across consumer-magazine and trade-publication swabs), and the upstream illness route — cross-contamination from raw poultry — is one of the better-characterized pathogenic pathways in domestic microbiology, carrying a population burden of millions of cases per year in the US alone (Scallan et al. 2011) (Luber 2009). Knives and blocks sit on that route. The intervention is free, the protocol is trivial, and the downside risk of complying is zero. As a hygiene call, this is one of the higher signal-to-effort entries available in a domestic kitchen.
Skeptic case
No randomized trial has shown that a person who dries their knife and brushes their block monthly suffers fewer enteric infections than a person who does not. The illness-route arrow runs through cross-contamination generally; the marginal contribution of the block specifically is plausible but unquantified. Two epidemiological studies cited by Cliver found that cutting-board cleaning habits had little measurable effect on sporadic salmonellosis incidence — the dominant signal was raw-poultry handling and hand-washing (Cliver 2006). It is entirely possible that the block contributes less to household illness than the headlines suggest, and that the entry's strongest honest pitch is the knife-edge protection plus low-grade mold removal rather than illness prevention.
Author's call
Lands optimist on the protocol, soberly modest on the score. The mechanism and prevalence evidence are strong enough to recommend the practice without hedging; the population-level illness reduction is real but small in absolute terms — this is one of perhaps a dozen kitchen-hygiene practices that collectively bring the cross-contamination risk down, not a single high-leverage move. The entry's lead is the knife-care payoff plus the hygiene-reservoir cleanup, with foodborne-illness reduction as the secondary lift. Evidence rates 3 (consistent observational data, strong mechanism, no RCT); controversy rates 1 (universal agreement on the direction, mild disagreement on the magnitude).
Stakeholder and incentive map
- Knife manufacturers push hand-wash, dry, sheath-when-dry — their warranties depend on it, and the protocol is genuinely correct.
- Knife-block manufacturers rarely advertise the cleaning protocol; the in-slot brush sold separately is a quiet acknowledgment.
- NSF International publishes the headline swab studies; its commercial business is certification, which gives it an incentive to surface kitchen-hygiene findings — directionally aligned with the call but worth noting.
- Magnetic-strip and in-drawer-tray makers have a competing-product incentive to overstate block risks; their hygiene argument is real but commercially convenient.
- Public health agencies (FDA, USDA-FSIS, CDC) emphasize hand-washing and cross-contamination broadly; block-specific guidance is rarer and mostly downstream of NSF's framing.
Population variability
Effect is broadly universal — any kitchen with a slotted wooden block is in scope. Higher leverage in:
- Households with immunocompromised members or older adults — lower infectious dose, higher consequence.
- Households where raw poultry is prepared frequently — the cross-contamination route is loaded more often.
- Humid climates — the slot dries even more slowly; mold accelerates.
- Owners of higher-end carbon-steel or high-hardness stainless knives — the corrosion penalty for wet sheathing is faster and more visible.
Knowledge gaps
No RCT directly tests block-hygiene practice against household illness incidence — the study would be hard to recruit and harder to keep blinded. Quantitative transfer rates from a contaminated slot back onto the next-used blade are not well-characterized; most experimental cross-contamination studies use freshly-inoculated boards rather than aged slot biofilms. The relative contribution of "dirty slot" versus "wet sheathing" to corrosion is not separately measured. None of these gaps changes the practical recommendation; they bound how aggressively to claim a numeric illness-reduction benefit.
Scope and narrowing. The brief named knives, blocks, moisture and crumb traps, mold and bacterial growth, cross-contamination onto blades, edge corrosion, and cleaning/drying practice. All six are covered. The entry intentionally does not pull in cutting-board hygiene, sponge/dishcloth contamination, or sharpening protocol — each is substantial enough to warrant its own entry and is flagged in out-of-scope.
Rating difficulties. Evidence at 3 was the hardest call. The mechanism is direct and well-cited; the swab studies are consistent across consumer and trade sources; the upstream cross-contamination route is one of the better-characterised pathways in domestic food microbiology. But no RCT (and probably never one) ties the specific practice of block-hygiene to household illness incidence, and Cliver (2006) cites epidemiology where cutting-board cleaning habits didn't move the salmonellosis needle much — hand-washing dominated. 3 honours both the strong mechanism and the missing-trial gap; 4 felt like over-claiming. Health_short_term at 2 and longevity at 1 are conservative for the same reason: the per-household magnitude is real but small and unquantified.
Applicability at 4, not 5. Most adult households have kitchen knives and prepare some food at home — but a meaningful share of households don't own a slotted block specifically (in-drawer trays, magnetic strips, single all-purpose knife in a drawer). 4 anchors on "most adults" rather than "nearly everyone."
Dream narrative — relief lever, not aspiration. Overall score lands at ~22, so a narrative is optional. Wrote one anyway because the honest hook is a small, concrete relief story (stop two ongoing losses), and the dek and tagline land sharper with it than they would written cold. Aspiration framing would have rung false on an entry whose payoff is the absence of two things you weren't measuring.
Future links. Cross-link candidates when they exist: cutting-board hygiene, sponge/dishcloth replacement, knife sharpening, raw-poultry handling. None drafted yet.
Separate-entry candidates surfaced. Dishwasher chemistry and what it does to knife edges deserves a tighter standalone if a kitchenware category builds out; same for in-drawer storage geometries.
Voice call. Anchored on the dual payoff (knife edge + reservoir cleanup) because the foodborne-illness arrow alone is hard to claim honestly at this magnitude. The relief-lever framing carries the entry; the illness story is the secondary lift, scoped accurately.
Kitchen Knife and Block Hygiene
Sixty seconds of drying per use plus 10–15 minutes of block cleaning monthly. Trivial once the routine settles.
Strong mechanism, consistent observational swabs (NSF 2013), well-characterised cross-contamination pathway from raw poultry (Luber 2009, Trang 2022), foundational wood-vs-plastic surface work (Ak/Cliver/Kaspar 1994). No randomised trial linking block-specific hygiene practice to household illness incidence — score reflects the gap.
Removing a damp microbial reservoir from contact with the daily knife shaves a small share off the household's cross-contamination risk for non-typhoidal Salmonella and Campylobacter — the leading bacterial foodborne pathogens, ~3M US illnesses/year combined (Scallan 2011). The per-household magnitude is modest; the direction is consistent and the mechanism well-mapped (Luber 2009).
Foodborne illness mortality is small in absolute terms (~3,000 US deaths/year across all pathogens) and the block's specific contribution is one input among many. Real but marginal at the lifetime scale.